20 ABSTRACTS OF CHEMICAL PAPERS. Min e r a1 o gi c a Z C h e mi s t ry. Bismuth Minerals from Gladhammar. By G. LINDSTR~X (Jahrb. j*. Mia., 1890, ii, Ref. 53; from Ge6l. FiirPn. Forhand., 11, 771).-On examining a series of ores, tbe atithor found a lead-grey to tin-white mineral with a brilliant lnstre. On analysis, it gave the following results :- Bi. Pb. Ca. Fe. Zn. S. Insol. Total. 33.84 48-05 0.69 0-16 0-05 15-92 0-45 99-16 The author is unacquainted with a mineral of this coniposition (compere, lrowever, lillianite, 3Ph(Ag)S + Bi,S,). As an assay of another specimen gave 42.15 per cent. of lead, it is Hamlinite, a New Rhombohedra1 Mineral. By W. E. HIDDEN ant1 S . L. PEKF~ELD (Amer. J. Sci., 39, 511--.’13).-Shortly after t h e discovcry of ‘taerderite (Abstr., 1884, 827, 11 02) at Stoneham, Maine, this mineral was detected occurring as miniite, rhombohedra1 crvstals, :issoc*iated with herderite, margarodite, and the rare glucinum silicate, hertrandite.During the past five years, the authors have kept up a diligent search €or the crystals, but without success. The crystals are hexagorial-rhombohedritl, and vary from 1 to 2 mm. in diameter.. Their hardness is 45, and their sp. gr. 3.229. Qualitative analysis indicates that the mineral is a new species-a phosphate, probably of glucinum and aluminium, containing fluorine. The authors propose for it the name of humliiiite, in honour of Dr. A. C, Hamlin, who is largely interested in the development of the mineral resources of the district in which the new mineral occurs. The formula deduced from these results is 3PbS + Bi,S,.possible that bjelki te also occurs a t Gladhammar. €3. €3. B. B. H. B. Preparatioa of Artificial Molybdenite. By A. v. SCHULTEN (Jahrb, ,f. X t z . , 1890, ii, Ref. 223 ; from Geol. Foren,. b’orAa~~dZ., 11, 401).-The author melted 4 gleams of potassium carbonfite with 6 grams of sulphur in a porcelain crucible, and on cooling added 1 gram of molybdic anhydride. ‘J’he mass was then heated in a well- closed c.rucible to a melting heat, and, on cooling, a fresh portion of the anhydride was added. The process was repeated until 5 t o 6 grams of molgbdic anhydride had been used. On boiling the melted Ilianti with water, a residue of pure crystallised molybdenite, Mod,, was obtained in the form o€ greyish-violet, opaque, hexagonal crystals with a sp.gr. of 5.06 a t 15”. The crystah are very soft, and make grey marks on paper. Flinkite and Heliophy llite from Harstigen Mine, Sweden. By A. HAMBERG (Jahrh. j‘. Miu., 1890, ii., Ref. 834-228, from Geol. Fiiren. ForhundZ., 11, 21 2).-Flinkite, a hydrated manganese arsenate, occurs in khe Harstigen mine, Pajsberg, Wermland, iu greenish-brown crystals with sarkinite on karyopilite. Its sp, gr. is B. H. B.MINERALOGICAL CHEMISTRY. 2 1 3.87. rhombic system, the forms observed being UP, Pm, P, mP00. analysis, it gave results corresponding with the formula, It has a hardness of more than 4, and-crystallise_s in the OIL 4H20,.EMn0,Mn203,As206, a composition very similar to that of sjnadelphite. An optical exauiinntion of the mineral heliophyllite, described by G.Flink as biaxial, showed i t to be always composed of biaxial and uniaxial portions. The author distinguishes two types of this mineral as met with at the Harstigen mine : (1) the coarsely lami- nated variety ; and (2) crystals associated with baryytes and inesite. The optical properties exhibited are similar t o those shown by the mineral ekdemite from Lingban, described by Nordenskiold as optically uniaxial. Further, the minerals appear to be chemically identical, analysis having given the following resnlts :- PbO. FeO + MnO. CaO. A S , ~ , . Sb203. CI. 10.60 - 8.00 11.. . . . . 81.03 0-07 0.08 19.85 0.56 8.05 111.. . . . . 80.99 0.16 0.11 10.49 1.38 7.96 I.. . . . . 83.45 - - 1. Ekdemite (Nordenskiold). 11. Heliophyllite, type I.I11 the same, type 11. Nordenskiiild calculates the fbrrniila, Pb5As208 + 2PbC12, Flink gives PbcAs2O7 + 2PbC1,. The author, however, is of opinion that the more exact formula Pb,As,O,, + 4PbC12 is not improbable. B. H. B. Minerals from Styria. By E. HATLE and H. TAUSS (Jak-b. f. .illit!., 1890, ii., Ref. 1 7 ; from Vwhandl. geol. Reichsanst., 1887, 226-229) .--1 . Pharmacolite from Viillig. 'l'his mineral occurs in ~ h i t e , trauslucent groups of' crystals and crusts with B fibrous texture. As.205. CaO. H,O. 48-60 27-04 24.49 Analjsis yielded the following results :- The mineral is associated with zinc-blende, plena, arsenical pyrites, magnetic pyrites. iron pyrites, quartz, and calcite. 2. Iron-gjmnite from Kraubath. This mineral occurs, with yellow gjmnite, in serpentine.It ha's a hardness of 3, and a sp. gr. of 1.986. Analysis yielded the folIowing results :- SiO,. MgO. FeO. H2O. 41-55 30.24 6.60 20.10 Allowance being made for 1-27 per cent. of ferric oxide dissemi- nated in tlie form of iron mica, the formula is H,,Mgl2E'eSl1O,, + 9HZO. B. H. B. Fluorine and the Synthesis of Minerals. By S. MEUEIER (Compt. 1-end., 111, 509-51 1) .-The iise of aluminium fluoride makes it pomihle to obtain in a compratively short time, and at the tempe-22 ABSTRACTS OF CEIEMICAL PAPERS. rature of an ordinai-y coke fire, several minerals, which under ordinary conditions are difficult to synthesise. 32 parts of calcined silica, 8 parts of fused potassium hydroxide, and 44 parts of aluminium fluoride, yield a regulus which is not completely vitreous but gives a fracture with a silky lustre.Under the microscope, it is seen to contain needles of sillimanite and hexa- gonal lamella of tridymite i n large quantity, together with inclusions of various kinds and globuliform masses which are almost opaque. 43 parts of silica, 20 of calcium oxide, and 60 of aluminium fluoride yield a product which, although chiefly a glass, has a highly lustrous fracture, and contains needles of sillimanite and lamellae of trid ymite. 26 parts of silica, 12 of calcium oxide, 2 of potassium hydroxide, and 25 of aluminium fluoride yield. a decidedly crystalline product containing large quan t.ities of thin plates of labradorite, many of which are macled according to the albite law, whilst the larger have spheroidal inclusions.22 parts of silica, 17 of alumina, 0.2 of ferric oxide, 8 of sodium hydroxide, '2 of potassium hydroxide, and 1 of lime, in a crucible brasqued with cryolite, jie!d a deep grey granulo-crystalline product. The mass is vitreous, but is fuli of inclusions, and contains many crystals of sillimanite, and a large quantity of prismatic crystals of nepheline. 27 parts of silica, 12 of alumina, and 10 of potlassium hydroxide in B crucible brasqued with cryolite, yield a partially vitreous product f u l l of crystalline granules. Under the microscope, largc! numbers of smd1 globules are seen, identical with the leucite of natural amphigenes. C. H. B. Sigterite, a New Felspar. By C. RAMMELSREKG (,Juhrb.f. Min., 1890, ii, Mem. 71--74).-1n an investigation into the properties of eu- dialyte from Sigtero, the author found that this mineral was associated with two others, white albite and another felspar in the form of grey, granular particles.The new felspar has the cleavage of ort'hoclase, and, chemically, is a potassium sodium felspar free from lime, and much more basic than albite and orthoclase. I n thin sections, in- clusions of augite and a small quantity of magnesia-mica were observed. After making corrections for the small quantities of augite present, the mineral gives on analysis the following results :- SiOz. A1,0,. Na,O. KzO. Total. 50.01 30.86 13.90 523 100.00 The formula of the felspar is therefore (NaK),AISi,Olo. words, i t is a combination of albite and an alkali anorkhite. same time, it has the composition of an anhydrous natrolite.I n other At the B. H. B. Minerals from Vesuvius. By E. SCACCHI (Zeit. K?-yst. Min., 18, 99-102; from R. Accud. d i Napoli, 3888, 12).-1. l'hakellite, i~ new mineral. Among the Somrna minerals in the ninseum of the University of Naples there is a substance, hitherto undescribed, whichMINERALOGICAL OHEMISTRY. 23 the author has named from its characteristic combination of trans- parent, colourless needles to white, silky bundles (@&Xhr). This rare mineral occurs in a rock consisting of augite with more or less mica, and occasionally in grey, granular calcite. Optically the mineral is uniaxial, with faint negative birefraction, and therefore belongs to the hexagonal system. It has the hardness of orthoclase, and a sp. gr.of 2.49. Analysis gave the following results :- SiO,. A1,0,. K20. Na,O. Total. 37.73 33.33 29.30 0.37 100.73 Formula : K2A12Si208. 2. Thernioncitvite, from the lava of 1859. The analogy with nepheline is remarkable. This mineral is new for Vesuvius. The Naples museum recently received numerous white, opaque, drusy incrustations from the Fosso grande. On analysis, this mineral, Na,CO, + HzO, yielded 35-44 per cent. of carbonic anhjdride. 3. Soda from the interior of the same lava in crystalline, colour- less, transparent grains. On analysis, the following results were obtaked :- CO,. Na,O. K20. H20. Total. 15.91 22-15 0.41 61.68 100.15 These results correspond with the formula Na,C03 + lOH,O. The mineral cannot have been produced by sublimation, but by the action of carbonic anhjdride which has decomposed the lava and taken the soda from it.4. Altered cowpfonite from the Somma conglomerates. In one yariety of conglomet ate at Vesuvius, zeolites occnr ill association with calcite. Among these, small crystals resembling comptonite are occasionally met with, the change in the chemical composition of the zeolites and the variation from that of comptonite consisting chiefly in a loss of water, an absorption of calcium carbonate, and a change in the ratio of the silica, to the alumina, (compare Abstr., 1887, 17). B. H. B. Amphibolite from Habendorqrin Silesia. By E. DATHE ( J a h ~ h . $. Min., 18W, ii, Ref., 243-244 ; from Jalwb. preuss. geol. Landesnnst., 1889, 309-328) .-The amphibolite (Analysis I) occurring in the hiotite gneiss of Habendorf, consists of hornblende of a greenish-black colour and bdliant lustre.There is a second variety (Analysis 11) composed of light greenish-grey hornblende, with a little pyrrhotite and mica. Under the microscope, olivine, diopside, chromite, and rutile could also be detected. SiO,. Ti02. Fe20,. Cr,O,. Al,O,. FeO. MgO. CaO. I . . 46.47 0.21 4.18 trace 8.68 3.73 22.79 9-05 11 . . 47-82 0.65 0.94 0.65 7.88 3-50 29-56 3.66 42,O. Na20. H,O. CO,. Total. Sp. gr. I .. 0.35 1.14 3.39 - 99.99 2.959 11.. trace 0.43 4.20 0.41 99.48 2.857 B. H. B.24 ABSTRAOTS OF CHEMICAL PAPERS. Chemical Nature of Tourmaline. By C. RAMW ELSRERG (Ju7wb. f. JIi,t., 1890, ii, Mem., 149--162).-1n this paper the author re- calculates some 70 analyses of tourmaline, with a view to controvert the formula: recently arrived a t by Riggs (Abstr., 1888, 660), Jan- nasch and Calb (Abstr., 1889, 4 Z ) , Scharizer (Abstr., 1689, 764)) and Wiilfing (Abstr., 18r39, 765).He is slill of opinion that his interpre- tation of thc tourmaline analyses of 20 years ago was correct, eccording to which they must be regarded as isomorphous mixtures of thres silicates, R'$3iO5. R"3Si05, and R"Si05, in which R' represents H, Na, K, Li ; R" represents Fe, M L ~ , Mg, Ca ; and Rvi represents A12, Fez, B,, Cr2. By G. W. KALB (Jnhd. f. Min., 1890, ii. Ref. 199-203 ; from Innug. Diss. Gottinge,/,, 1890).-Ten varieties of tourmaline analysed by the author may be divided into t.hree groups :-( 1) Lithium tonrmaline, (2) iron magnesium tour- maline, (3) iron tourmaline.From the analyses, the author deduces the general formula R,BO,(SiOa),. [The analyses given appear to be almost identical with those given in a paper by P. Jannasch and G. Cslb (Abstr., 1889, 472).] By M. KOCH (Jah~b. f. Mh., 1830, ii, Ref. 244-245 ; from Zeit. deutsch. geol. Ges., 41, 163-165).- Peridotite occurring in the gabbro mass of the Kaltenthal, in the Harz, contains olivine in angular grains, as much as 23 mm. in size, with biotite, spinel, and titaniferous iron ore. Small quantities of augite and plagioclase are present as accessory constituents. The rock is more basic than any of the basic members of the Harzburg gabbro hitherto examined, as ir, shown by the following analytical results, in which the high percentage of titanium is probably due to tlie biotite :- SiOz. Ti02.Al20,. Fe,O,. FeO. MgO. CaO. K20. 34.98 5.18 10.80 1.42 21.33 19.30 0.43 5.42 NazO. H2O. 503. Total. Sp. gr. 0.17 1:28 trace 100.31 3.27 B. H. H, Composition of Tourmaline. B. H. €3. Peridotite from the Harz. B, H. B. Minerals of the Garnet Group. By W. C. BROGGER and H. HACKSTROM (Zeit. Kvyst. iWin., 18, 209-276).-0f the 12 silicates crystallieing in the regular system, eulytine, zunyite, helvine, danalite, garnet, sodalite, nosean, lapis-lazuli, leucite (maskelynite), pollux, analcirue, aiid faujnsite, the first eight are orthosilicates, and the last four metasilicates. Three of the metasilicates, maskelynite, pollux, and analcirne! belong to one morphological group, whilst faujasite is an isolated species of octahedral type. The orthosilicates are regarded by the author as forming one large group, the garnet group, which may be subdivided into two divisions :-(1) Orthosilicates of tetrahedral character, and (2) orthosilicates of rhom bic dodeca- hedral character.This second division includes holohedral members (the garnet series proper), as well as liemihcdral ones (the alkali Q arn e t s) .MINERALOGICAL OHEMISTRT. 25 The formula? of the members of the first division are as foi1ow.s:- Eulytine ...... Bi4(SiO&. Zunyite . . . . . . Danalite. . . . . . Helvine . . . I . . [A16F2C1(0H),]Al,(SiO~)3. (FeZnMn),[ (ZnFe)zS]Be3(Si04),. (MnE'eCa),(Mn,S)Be,(Si04j3. In this voluminous paper, the author brings forward a mass of facts to prore t,he close connection of the regular orthosilicates.The analyses of all the mineials of this garnet group lead to f o r m u l ~ in which there is 1 mol. of an orthosilicate with 3 mols. of silicic acid. All the members of this group, too, belong to the regular system. A very large number of analyses are discussed. Of these, the followiug have not previously been published : - SiO,. A1,O. I. 36.74 31.96 11. 37-24 31.60 111. 31.65 27.03 IV. 31.99 2732 v. 32.30 27.38 VI. 32-20 27-37 PII. 32.52 %7%1 VIII. 39-48 27-62 IX. 53.13 1.76 X. 55.15 - XI. 55.55 - CaO. 0.2 1 - 9-94 8.21 8.18 6.47 6.60 24.il 26.38 25.95 MgO. Na,O. K20. SO,. 8. C1. HzO. - 85.95 trace 0.11 - 7.11 9.17 25-60 - - - 7.31 - 27.26 - 14.06 - - - - 16.53 - 14.22 - - - 0.11 18.03 0.35 12.62 0.44 0.31 - 0.11 17.98 0.35 13.17 0.46 0.33 - - - - 19.4.5 0.28 10.46 2.71 0.47 - - 19.84 0-29 10.47 2.71 0.47 0.07 16.93 2.62 - - - - 1.31 18.47 - - - - - - 18.52 - __ - - - - I.Sodalitc. 11. Results calculated from the formula Na4( A1 Cl) Al,( SiO,),. 111. Nosean, formula Na4( A1[S04Na]) AlZ(SiO4),. TV. Hauyn, formula Nil,Ca[Al( SO4Na)]Al,( SiO,),. V. Hauyn, analysis. V1, Results calculated from 92 mols. hauyn, 5.2 mols. sodnlite, and 2.7 mols, ultramarine with the formula Na4[A1( S,Na)]A12( SiO,),. VII. Lapis- lazuli. VIII. The same, results calculated from a composition of '76 9 mols. hauyn, 15.7-mols. ultramarine, and '7.4 mols. sodalite. IX. Diopside occurring enclosed in lapis lazuli. X. Results after sub- traction of 8 per cent. lazurite. XI. Results corresponding with formula CaMg( SiO,),. J3. H B. Minerals and Roouks in the Diamond Fields of South Africa.By A. KNOP (Jlrhrt.f. Min., ii, Ref. 97--99).-Tlie matrix of the diamonds, the so-called blue earth, is found on examination to behave like a serpentine which, after decomposition by acid, leaves inicroliths of pyroxenic character. The rock may be described as a serpentine-tuff enclosing, at Jagersfontein, the following minerals : garnet, chrome-diopside, enstatite, chromite, zircon, apatite, idocrase. ~utile, mica, and diamond. These minerals are described in detail by the author, who gives analyses of the chrome-diopside and chrome- irou ore. The author regards the Jagersfontein deposit as having been formed26 ABSTRAUTS OF CHE1\1ICAL PAPERS. from a peridotite, which has been mechanically broken up and trans- ported to a favourably situated locality, where it has become ser- pentinised.The relation of the diamond to the peridotite is thought to be analogous to the occurrence of the diamond in meteorites. B. H. B. Natural Cement from Cairo. By E. SICKENBERGER (Jnhrb. ,f. E n . , 1890, ii, Ref. 275-276; from Zeii. deutscta. geol. Ges., 41, 312--318).-0n the railway between Abbasijeh and Citadelle, near Cairo, there occur stalactitic masses hitherto thought to have been geyser deposits. On examination, they are found to consist of cemented quartz sands, approximating in composition t o artificial mortar. Sand. SiO,. CaO. A1,0, i- Fe20,. GO,. H,O. MgO. SO,. NaC1. 4$90 6-24 22.80 1-47 14.00 3-83? 3-58 0.58 0.24 B. H. B. Obsidian Cliff, Yellowstone National Park. By J. P.IDDINGS (Seventh Awnual Rep. U.X. Geol. Survey, 249-29.i).-The author describes in detail, in a monograph of 4!4 pages, illustrated by 51 plates, the geological occurrence, lithological structure, petrographical and microscopical cliamcters of 0 bsidian Cliff, at the northern end of Beaver Lake, in the Yellowstone National Park. Though obsidian of nearly the same chemical composition occurs in all parts of the world, the obsidian flow at Beaver Lake is especially remarkable for its unsurpassed extent and thickness. lt is the only known occurreuce of rhyolitic obsidian in which a distinctly columnar structure has been developed. It is entirely free from porphyritic crystals, and abounds in spherulitic structures and lithophysm. These are undoubtedly of primary cry stallisation out of a molten glass, which was graduallj- cooling.Since its solidification, too, no alteration, chemical o r mechanical, has taken place. Analyais yielded the following results :- B. H. l3. Eruptive Rocks of the Cab0 de Gata. By A. OSANN (Jahrh. .f. illin., 1890, ii, Ref., 268-270 ; from Zeit. deutsch. geol. GPS., 41, 297-311) .-The author describes in detail the occurrence of eruptive rocks at the Cab0 de Gata, Almeria, Spain. The predominating rocks are andesites, dacites, and liparites. Basalts are eritirelg absent, as also are nephelirie and leucite rocks. Only one rock contains olivine. This occurs in the vicinity of Vera and is described by Calderon as limburgite. It is the youngest of the eruptive rocks of the district, and on analysis gave results approximating most closely to those obtained with olivine-bearing lamprophyres, such as the rninette of the Ballon d’lilsace.l n the rock, biotite only is visible t o the naked eye, whilst olivine, augite, and a little felspar can be detected under the microscope. The analytical results were as follows :- Si02. AI20,. Fe2O3. FeO. MnO. MgO. CaO. K,O. Ne,O. 55.17 13.49 3.10 3-55 0.39 8.55 3.15 1.09 4-43 H,O. 60,. Total. 4.27 3-27 100.46MINERALOOICJAL CHEMISTRY, 27 The rock is named Verite by the author. It should certainly not Meteoric Iron from Magura, Arva, Hungary. By E. WEINSCHENK (Jahrh. f. M ~ ! L . , 1890, ii, Ref. 57-59 ; from Ann. k. k. Hof- nausewms, 4, 93-101 ; compare Berthelot and Friedel, Abstr., 1890, 1384).--In an investigation of the meteoric iron from Magura, Arra county, Hungary, the author succeeded in isolating the following constituents :-- 1.Tin-white regular crystals, hitherto regarded as schreibersite. These appear to have a cleavage perpendicular to the longitudinal axis ; they are stronglp magnetic, very brittle, and soluble in hydro- chloric acid and copper ammonium chloyide, with separation of carbon. The hardness is 54 t o 6, and the sp. gr. 6.977. Analysis (No. I) gave, after subtraction of schreibersite, results corresponding with the formula C(FeNiCo),. For this new mineral, the author proposes the name of cohsnite. d. Thin, silver-white, strongly magnetic lamellq which are but slowly soluble in hydrochloric acid, and which may represent Reichenbach’s t m i t e . The composition (Analysis 11) is in accord with the formula Fe,(NiCo)2.3. Fragments of various shapes, which form the principal maw of the iron. They are highly magnetic, sparingly soluble in hydro- chloric acid, and give on analysis (Xo. IlIj results corresponJing with the formula Fe,(NiCo). The high percentage of cobalt is noteworthy- be classed as a limburgite. B. H. B. Fe. Xi. Co, C. Cu. Sn. Schreibersite. Total. I. 89.83 3.08 0.79 6.43 trace trace 0.63 100*78 11. 71.04 26.64 1.67 0.30 - - - 99.65 111. 87.96 9.19 2.60 0.36 - - - 100.11 4. Crystals of rhornbic mid monoclinic augite. 5. Grains of partly isotropic, partly feebly bi-refractive, diamond proved to be harder than ruby and to burn to carbonic anhydride in a current of oxygen. Colvurless or strongly pleochroic blue grains appear to consist of curundum, whilst small, colourless aggregates may be tridymite.The author compares the varieties of carbon met with in meteoric iron with thoRe in pig iron. The “ hardening-carbon ” corresponds with the carbon given off in the form of hydrocarbons when the meteoric iron is dissolved in hydrochloric acid ; the ordinary carbide carbon corresponds with cohenite ; the grnphitic tempering-carbon Ivith the carbon in the residue when meteoric iron is dissolved ; and, lastly, graphite is met with in both varieties of iron. This perfect analogy leads to the assumption that the conditions under which meteoric iron was formed are coniparable to those under which pig iron is produced, and the presence of the diamond indicates that the carbon dissolved or chemically combined in iron can under certain conditions separate oat in the allotropic form of the diamond.B. H. B.20 ABSTRACTS OF CHEMICAL PAPERS.Min e r a1 o gi c a Z C h e mi s t ry.Bismuth Minerals from Gladhammar. By G. LINDSTR~X(Jahrb. j*. Mia., 1890, ii, Ref. 53; from Ge6l. FiirPn. Forhand., 11,771).-On examining a series of ores, tbe atithor found a lead-grey totin-white mineral with a brilliant lnstre. On analysis, it gave thefollowing results :-Bi. Pb. Ca. Fe. Zn. S. Insol. Total.33.84 48-05 0.69 0-16 0-05 15-92 0-45 99-16Theauthor is unacquainted with a mineral of this coniposition (compere,lrowever, lillianite, 3Ph(Ag)S + Bi,S,).As an assay of another specimen gave 42.15 per cent. of lead, it isHamlinite, a New Rhombohedra1 Mineral.By W. E. HIDDENant1 S . L. PEKF~ELD (Amer. J. Sci., 39, 511--.’13).-Shortly after t h ediscovcry of ‘taerderite (Abstr., 1884, 827, 11 02) at Stoneham, Maine,this mineral was detected occurring as miniite, rhombohedra1 crvstals,:issoc*iated with herderite, margarodite, and the rare glucinum silicate,hertrandite. During the past five years, the authors have kept up adiligent search €or the crystals, but without success. The crystalsare hexagorial-rhombohedritl, and vary from 1 to 2 mm. in diameter..Their hardness is 45, and their sp. gr. 3.229. Qualitative analysisindicates that the mineral is a new species-a phosphate, probably ofglucinum and aluminium, containing fluorine. The authors proposefor it the name of humliiiite, in honour of Dr.A. C, Hamlin, who islargely interested in the development of the mineral resources of thedistrict in which the new mineral occurs.The formula deduced from these results is 3PbS + Bi,S,.possible that bjelki te also occurs a t Gladhammar. €3. €3. B.B. H. B.Preparatioa of Artificial Molybdenite. By A. v. SCHULTEN(Jahrb, ,f. X t z . , 1890, ii, Ref. 223 ; from Geol. Foren,. b’orAa~~dZ., 11,401).-The author melted 4 gleams of potassium carbonfite with6 grams of sulphur in a porcelain crucible, and on cooling added1 gram of molybdic anhydride. ‘J’he mass was then heated in a well-closed c.rucible to a melting heat, and, on cooling, a fresh portion ofthe anhydride was added. The process was repeated until 5 t o 6 gramsof molgbdic anhydride had been used.On boiling the melted Iliantiwith water, a residue of pure crystallised molybdenite, Mod,, wasobtained in the form o€ greyish-violet, opaque, hexagonal crystalswith a sp. gr. of 5.06 a t 15”. The crystah are very soft, and makegrey marks on paper.Flinkite and Heliophy llite from Harstigen Mine, Sweden.By A. HAMBERG (Jahrh. j‘. Miu., 1890, ii., Ref. 834-228, fromGeol. Fiiren. ForhundZ., 11, 21 2).-Flinkite, a hydrated manganesearsenate, occurs in khe Harstigen mine, Pajsberg, Wermland, iugreenish-brown crystals with sarkinite on karyopilite. Its sp, gr. isB. H. BMINERALOGICAL CHEMISTRY. 2 13.87.rhombic system, the forms observed being UP, Pm, P, mP00.analysis, it gave results corresponding with the formula,It has a hardness of more than 4, and-crystallise_s in theOIL4H20,.EMn0,Mn203,As206,a composition very similar to that of sjnadelphite.An optical exauiinntion of the mineral heliophyllite, described byG.Flink as biaxial, showed i t to be always composed of biaxial anduniaxial portions. The author distinguishes two types of thismineral as met with at the Harstigen mine : (1) the coarsely lami-nated variety ; and (2) crystals associated with baryytes and inesite.The optical properties exhibited are similar t o those shown by themineral ekdemite from Lingban, described by Nordenskiold asoptically uniaxial. Further, the minerals appear to be chemicallyidentical, analysis having given the following resnlts :-PbO. FeO + MnO. CaO.A S , ~ , . Sb203. CI.10.60 - 8.0011.. . . . . 81.03 0-07 0.08 19.85 0.56 8.05111.. . . . . 80.99 0.16 0.11 10.49 1.38 7.96I.. . . . . 83.45 - -1. Ekdemite (Nordenskiold). 11. Heliophyllite, type I. I11 thesame, type 11. Nordenskiiild calculates the fbrrniila, Pb5As208 +2PbC12, Flink gives PbcAs2O7 + 2PbC1,. The author, however, is ofopinion that the more exact formula Pb,As,O,, + 4PbC12 is notimprobable. B. H. B.Minerals from Styria. By E. HATLE and H. TAUSS (Jak-b. f..illit!., 1890, ii., Ref. 1 7 ; from Vwhandl. geol. Reichsanst., 1887,226-229) .--1 . Pharmacolite from Viillig. 'l'his mineral occurs in~ h i t e , trauslucent groups of' crystals and crusts with B fibroustexture.As.205. CaO. H,O.48-60 27-04 24.49Analjsis yielded the following results :-The mineral is associated with zinc-blende, plena, arsenicalpyrites, magnetic pyrites.iron pyrites, quartz, and calcite.2. Iron-gjmnite from Kraubath. This mineral occurs, with yellowgjmnite, in serpentine. It ha's a hardness of 3, and a sp. gr. of 1.986.Analysis yielded the folIowing results :-SiO,. MgO. FeO. H2O.41-55 30.24 6.60 20.10Allowance being made for 1-27 per cent. of ferric oxide dissemi-nated in tlie form of iron mica, the formula is H,,Mgl2E'eSl1O,, +9HZO. B. H. B.Fluorine and the Synthesis of Minerals. By S. MEUEIER(Compt. 1-end., 111, 509-51 1) .-The iise of aluminium fluoride makesit pomihle to obtain in a compratively short time, and at the tempe22 ABSTRACTS OF CEIEMICAL PAPERS.rature of an ordinai-y coke fire, several minerals, which underordinary conditions are difficult to synthesise.32 parts of calcined silica, 8 parts of fused potassium hydroxide,and 44 parts of aluminium fluoride, yield a regulus which is notcompletely vitreous but gives a fracture with a silky lustre.Underthe microscope, it is seen to contain needles of sillimanite and hexa-gonal lamella of tridymite i n large quantity, together with inclusionsof various kinds and globuliform masses which are almost opaque.43 parts of silica, 20 of calcium oxide, and 60 of aluminiumfluoride yield a product which, although chiefly a glass, has a highlylustrous fracture, and contains needles of sillimanite and lamellae oftrid ymite.26 parts of silica, 12 of calcium oxide, 2 of potassium hydroxide,and 25 of aluminium fluoride yield.a decidedly crystalline productcontaining large quan t.ities of thin plates of labradorite, many ofwhich are macled according to the albite law, whilst the larger havespheroidal inclusions.22 parts of silica, 17 of alumina, 0.2 of ferric oxide, 8 of sodiumhydroxide, '2 of potassium hydroxide, and 1 of lime, in a cruciblebrasqued with cryolite, jie!d a deep grey granulo-crystalline product.The mass is vitreous, but is fuli of inclusions, and contains manycrystals of sillimanite, and a large quantity of prismatic crystals ofnepheline.27 parts of silica, 12 of alumina, and 10 of potlassium hydroxidein B crucible brasqued with cryolite, yield a partially vitreousproduct f u l l of crystalline granules.Under the microscope, largc!numbers of smd1 globules are seen, identical with the leucite ofnatural amphigenes. C. H. B.Sigterite, a New Felspar. By C. RAMMELSREKG (,Juhrb.f. Min.,1890, ii, Mem. 71--74).-1n an investigation into the properties of eu-dialyte from Sigtero, the author found that this mineral was associatedwith two others, white albite and another felspar in the form of grey,granular particles. The new felspar has the cleavage of ort'hoclase,and, chemically, is a potassium sodium felspar free from lime, andmuch more basic than albite and orthoclase. I n thin sections, in-clusions of augite and a small quantity of magnesia-mica wereobserved. After making corrections for the small quantities of augitepresent, the mineral gives on analysis the following results :-SiOz.A1,0,. Na,O. KzO. Total.50.01 30.86 13.90 523 100.00The formula of the felspar is therefore (NaK),AISi,Olo.words, i t is a combination of albite and an alkali anorkhite.same time, it has the composition of an anhydrous natrolite.I n otherAt theB. H. B.Minerals from Vesuvius. By E. SCACCHI (Zeit. K?-yst. Min., 18,99-102; from R. Accud. d i Napoli, 3888, 12).-1. l'hakellite, i~new mineral. Among the Somrna minerals in the ninseum of theUniversity of Naples there is a substance, hitherto undescribed, whicMINERALOGICAL OHEMISTRY. 23the author has named from its characteristic combination of trans-parent, colourless needles to white, silky bundles (@&Xhr). Thisrare mineral occurs in a rock consisting of augite with more or lessmica, and occasionally in grey, granular calcite. Optically themineral is uniaxial, with faint negative birefraction, and thereforebelongs to the hexagonal system.It has the hardness of orthoclase,and a sp. gr. of 2.49. Analysis gave the following results :-SiO,. A1,0,. K20. Na,O. Total.37.73 33.33 29.30 0.37 100.73Formula : K2A12Si208.2. Thernioncitvite, from the lava of 1859.The analogy with nepheline is remarkable.This mineral is new forVesuvius. The Naples museum recently received numerous white,opaque, drusy incrustations from the Fosso grande. On analysis, thismineral, Na,CO, + HzO, yielded 35-44 per cent. of carbonic anhjdride.3. Soda from the interior of the same lava in crystalline, colour-less, transparent grains.On analysis, the following results wereobtaked :-CO,. Na,O. K20. H20. Total.15.91 22-15 0.41 61.68 100.15These results correspond with the formula Na,C03 + lOH,O. Themineral cannot have been produced by sublimation, but by the actionof carbonic anhjdride which has decomposed the lava and taken thesoda from it.4. Altered cowpfonite from the Somma conglomerates. In oneyariety of conglomet ate at Vesuvius, zeolites occnr ill associationwith calcite. Among these, small crystals resembling comptonite areoccasionally met with, the change in the chemical composition of thezeolites and the variation from that of comptonite consisting chieflyin a loss of water, an absorption of calcium carbonate, and a changein the ratio of the silica, to the alumina, (compare Abstr., 1887, 17).B.H. B.Amphibolite from Habendorqrin Silesia. By E. DATHE ( J a h ~ h .$. Min., 18W, ii, Ref., 243-244 ; from Jalwb. preuss. geol. Landesnnst.,1889, 309-328) .-The amphibolite (Analysis I) occurring in thehiotite gneiss of Habendorf, consists of hornblende of a greenish-blackcolour and bdliant lustre. There is a second variety (Analysis 11)composed of light greenish-grey hornblende, with a little pyrrhotiteand mica. Under the microscope, olivine, diopside, chromite, andrutile could also be detected.SiO,. Ti02. Fe20,. Cr,O,. Al,O,. FeO. MgO. CaO.I . . 46.47 0.21 4.18 trace 8.68 3.73 22.79 9-0511 . . 47-82 0.65 0.94 0.65 7.88 3-50 29-56 3.6642,O. Na20. H,O.CO,. Total. Sp. gr.I .. 0.35 1.14 3.39 - 99.99 2.95911.. trace 0.43 4.20 0.41 99.48 2.857B. H. B24 ABSTRAOTS OF CHEMICAL PAPERS.Chemical Nature of Tourmaline. By C. RAMW ELSRERG (Ju7wb.f. JIi,t., 1890, ii, Mem., 149--162).-1n this paper the author re-calculates some 70 analyses of tourmaline, with a view to controvertthe formula: recently arrived a t by Riggs (Abstr., 1888, 660), Jan-nasch and Calb (Abstr., 1889, 4 Z ) , Scharizer (Abstr., 1689, 764)) andWiilfing (Abstr., 18r39, 765). He is slill of opinion that his interpre-tation of thc tourmaline analyses of 20 years ago was correct, eccordingto which they must be regarded as isomorphous mixtures of thressilicates, R'$3iO5. R"3Si05, and R"Si05, in which R' representsH, Na, K, Li ; R" represents Fe, M L ~ , Mg, Ca ; and Rvi representsA12, Fez, B,, Cr2.By G.W. KALB (Jnhd. f. Min.,1890, ii. Ref. 199-203 ; from Innug. Diss. Gottinge,/,, 1890).-Tenvarieties of tourmaline analysed by the author may be divided intot.hree groups :-( 1) Lithium tonrmaline, (2) iron magnesium tour-maline, (3) iron tourmaline. From the analyses, the author deducesthe general formula R,BO,(SiOa),. [The analyses given appear to bealmost identical with those given in a paper by P. Jannasch andG. Cslb (Abstr., 1889, 472).]By M. KOCH (Jah~b. f. Mh., 1830,ii, Ref. 244-245 ; from Zeit. deutsch. geol. Ges., 41, 163-165).-Peridotite occurring in the gabbro mass of the Kaltenthal, in theHarz, contains olivine in angular grains, as much as 23 mm. in size,with biotite, spinel, and titaniferous iron ore.Small quantities ofaugite and plagioclase are present as accessory constituents. Therock is more basic than any of the basic members of the Harzburggabbro hitherto examined, as ir, shown by the following analyticalresults, in which the high percentage of titanium is probably due totlie biotite :-SiOz. Ti02. Al20,. Fe,O,. FeO. MgO. CaO. K20.34.98 5.18 10.80 1.42 21.33 19.30 0.43 5.42NazO. H2O. 503. Total. Sp. gr.0.17 1:28 trace 100.31 3.27B. H. H,Composition of Tourmaline.B. H. €3.Peridotite from the Harz.B, H. B.Minerals of the Garnet Group. By W. C. BROGGER and H.HACKSTROM (Zeit. Kvyst. iWin., 18, 209-276).-0f the 12 silicatescrystallieing in the regular system, eulytine, zunyite, helvine,danalite, garnet, sodalite, nosean, lapis-lazuli, leucite (maskelynite),pollux, analcirue, aiid faujnsite, the first eight are orthosilicates, andthe last four metasilicates.Three of the metasilicates, maskelynite,pollux, and analcirne! belong to one morphological group, whilstfaujasite is an isolated species of octahedral type. The orthosilicatesare regarded by the author as forming one large group, the garnetgroup, which may be subdivided into two divisions :-(1) Orthosilicatesof tetrahedral character, and (2) orthosilicates of rhom bic dodeca-hedral character. This second division includes holohedral members(the garnet series proper), as well as liemihcdral ones (the alkaliQ arn e t s) MINERALOGICAL OHEMISTRT. 25The formula? of the members of the first division are as foi1ow.s:-Eulytine ......Bi4(SiO&.Zunyite . . . . . .Danalite. . . . . .Helvine . . . I . .[A16F2C1(0H),]Al,(SiO~)3.(FeZnMn),[ (ZnFe)zS]Be3(Si04),.(MnE'eCa),(Mn,S)Be,(Si04j3.In this voluminous paper, the author brings forward a mass offacts to prore t,he close connection of the regular orthosilicates. Theanalyses of all the mineials of this garnet group lead to f o r m u l ~ inwhich there is 1 mol. of an orthosilicate with 3 mols. of silicic acid.All the members of this group, too, belong to the regular system. Avery large number of analyses are discussed. Of these, the followiughave not previously been published : -SiO,. A1,O.I. 36.74 31.9611. 37-24 31.60111. 31.65 27.03IV. 31.99 2732 v.32.30 27.38VI. 32-20 27-37PII. 32.52 %7%1VIII. 39-48 27-62IX. 53.13 1.76X. 55.15 -XI. 55.55 -CaO.0.2 1-9-948.218.186.476.6024.il26.3825.95MgO. Na,O. K20. SO,. 8. C1. HzO.- 85.95 trace 0.11 - 7.11 9.1725-60 - - - 7.31 -27.26 - 14.06 - - -- 16.53 - 14.22 - - -0.11 18.03 0.35 12.62 0.44 0.31 -0.11 17.98 0.35 13.17 0.46 0.33 ---- 19.4.5 0.28 10.46 2.71 0.47 -- 19.84 0-29 10.47 2.71 0.47 0.0716.93 2.62 - - - - 1.3118.47 - - - - - -18.52 - __ - - - -I. Sodalitc. 11. Results calculated from the formulaNa4( A1 Cl) Al,( SiO,),.111. Nosean, formula Na4( A1[S04Na]) AlZ(SiO4),. TV. Hauyn, formulaNil,Ca[Al( SO4Na)]Al,( SiO,),. V. Hauyn, analysis. V1, Resultscalculated from 92 mols. hauyn, 5.2 mols. sodnlite, and 2.7 mols,ultramarine with the formula Na4[A1( S,Na)]A12( SiO,),.VII. Lapis-lazuli. VIII. The same, results calculated from a composition of'76 9 mols. hauyn, 15.7-mols. ultramarine, and '7.4 mols. sodalite. IX.Diopside occurring enclosed in lapis lazuli. X. Results after sub-traction of 8 per cent. lazurite. XI. Results corresponding withformula CaMg( SiO,),. J3. H B.Minerals and Roouks in the Diamond Fields of SouthAfrica. By A. KNOP (Jlrhrt.f. Min., ii, Ref. 97--99).-Tlie matrixof the diamonds, the so-called blue earth, is found on examination tobehave like a serpentine which, after decomposition by acid, leavesinicroliths of pyroxenic character. The rock may be described as aserpentine-tuff enclosing, at Jagersfontein, the following minerals :garnet, chrome-diopside, enstatite, chromite, zircon, apatite, idocrase.~utile, mica, and diamond.These minerals are described in detail bythe author, who gives analyses of the chrome-diopside and chrome-irou ore.The author regards the Jagersfontein deposit as having been forme26 ABSTRAUTS OF CHE1\1ICAL PAPERS.from a peridotite, which has been mechanically broken up and trans-ported to a favourably situated locality, where it has become ser-pentinised. The relation of the diamond to the peridotite is thoughtto be analogous to the occurrence of the diamond in meteorites.B. H. B.Natural Cement from Cairo. By E. SICKENBERGER (Jnhrb. ,f.E n . , 1890, ii, Ref. 275-276; from Zeii. deutscta. geol. Ges., 41,312--318).-0n the railway between Abbasijeh and Citadelle, nearCairo, there occur stalactitic masses hitherto thought to have beengeyser deposits.On examination, they are found to consist ofcemented quartz sands, approximating in composition t o artificialmortar.Sand. SiO,. CaO. A1,0, i- Fe20,. GO,. H,O. MgO. SO,. NaC1.4$90 6-24 22.80 1-47 14.00 3-83? 3-58 0.58 0.24B. H. B.Obsidian Cliff, Yellowstone National Park. By J. P. IDDINGS(Seventh Awnual Rep. U.X. Geol. Survey, 249-29.i).-The authordescribes in detail, in a monograph of 4!4 pages, illustrated by 51plates, the geological occurrence, lithological structure, petrographicaland microscopical cliamcters of 0 bsidian Cliff, at the northern endof Beaver Lake, in the Yellowstone National Park.Though obsidianof nearly the same chemical composition occurs in all parts of theworld, the obsidian flow at Beaver Lake is especially remarkable forits unsurpassed extent and thickness. lt is the only known occurreuceof rhyolitic obsidian in which a distinctly columnar structure has beendeveloped. It is entirely free from porphyritic crystals, and aboundsin spherulitic structures and lithophysm. These are undoubtedly ofprimary cry stallisation out of a molten glass, which was graduallj-cooling. Since its solidification, too, no alteration, chemical o rmechanical, has taken place.Analyais yielded the following results :-B. H. l3.Eruptive Rocks of the Cab0 de Gata. By A. OSANN (Jahrh..f. illin., 1890, ii, Ref., 268-270 ; from Zeit.deutsch. geol. GPS., 41,297-311) .-The author describes in detail the occurrence of eruptiverocks at the Cab0 de Gata, Almeria, Spain. The predominatingrocks are andesites, dacites, and liparites. Basalts are eritirelgabsent, as also are nephelirie and leucite rocks. Only one rockcontains olivine. This occurs in the vicinity of Vera and is describedby Calderon as limburgite. It is the youngest of the eruptive rocksof the district, and on analysis gave results approximating mostclosely to those obtained with olivine-bearing lamprophyres, such asthe rninette of the Ballon d’lilsace. l n the rock, biotite only is visiblet o the naked eye, whilst olivine, augite, and a little felspar can bedetected under the microscope. The analytical results were asfollows :-Si02.AI20,. Fe2O3. FeO. MnO. MgO. CaO. K,O. Ne,O.55.17 13.49 3.10 3-55 0.39 8.55 3.15 1.09 4-43H,O. 60,. Total.4.27 3-27 100.4MINERALOOICJAL CHEMISTRY, 27The rock is named Verite by the author. It should certainly notMeteoric Iron from Magura, Arva, Hungary. By E.WEINSCHENK (Jahrh. f. M ~ ! L . , 1890, ii, Ref. 57-59 ; from Ann. k. k. Hof-nausewms, 4, 93-101 ; compare Berthelot and Friedel, Abstr., 1890,1384).--In an investigation of the meteoric iron from Magura, Arracounty, Hungary, the author succeeded in isolating the followingconstituents :--1. Tin-white regular crystals, hitherto regarded as schreibersite.These appear to have a cleavage perpendicular to the longitudinalaxis ; they are stronglp magnetic, very brittle, and soluble in hydro-chloric acid and copper ammonium chloyide, with separation ofcarbon. The hardness is 54 t o 6, and the sp. gr. 6.977. Analysis(No. I) gave, after subtraction of schreibersite, results correspondingwith the formula C(FeNiCo),. For this new mineral, the authorproposes the name of cohsnite.d. Thin, silver-white, strongly magnetic lamellq which are butslowly soluble in hydrochloric acid, and which may representReichenbach’s t m i t e . The composition (Analysis 11) is in accordwith the formula Fe,(NiCo)2.3. Fragments of various shapes, which form the principal maw ofthe iron. They are highly magnetic, sparingly soluble in hydro-chloric acid, and give on analysis (Xo. IlIj results corresponJingwith the formula Fe,(NiCo). The high percentage of cobalt isnoteworthy-be classed as a limburgite. B. H. B.Fe. Xi. Co, C. Cu. Sn. Schreibersite. Total.I. 89.83 3.08 0.79 6.43 trace trace 0.63 100*7811. 71.04 26.64 1.67 0.30 - - - 99.65111. 87.96 9.19 2.60 0.36 - - - 100.114. Crystals of rhornbic mid monoclinic augite.5. Grains of partly isotropic, partly feebly bi-refractive, diamondproved to be harder than ruby and to burn to carbonic anhydride ina current of oxygen.Colvurless or strongly pleochroic blue grains appear to consist ofcurundum, whilst small, colourless aggregates may be tridymite.The author compares the varieties of carbon met with in meteoriciron with thoRe in pig iron. The “ hardening-carbon ” correspondswith the carbon given off in the form of hydrocarbons when themeteoric iron is dissolved in hydrochloric acid ; the ordinary carbidecarbon corresponds with cohenite ; the grnphitic tempering-carbonIvith the carbon in the residue when meteoric iron is dissolved ; and,lastly, graphite is met with in both varieties of iron. This perfectanalogy leads to the assumption that the conditions under whichmeteoric iron was formed are coniparable to those under which pigiron is produced, and the presence of the diamond indicates that thecarbon dissolved or chemically combined in iron can under certainconditions separate oat in the allotropic form of the diamond.B. H. B