The Orgueil meteorite consists of clay type minerals, carbonates, sulfates, iron oxides, elementary sulfur, and bituminous organic matter. It contains approximately 20 percent water, a part of which has deuterium/hydrogen ratios wholly different from terrestrial waters. The mineral texture of Orgueil resembles a pyroclastic sediment, leached by liquid water, yet the bulk chemical composition of this rock is very similar to the composition of the unfractionated primeval gas cloud. Hydrocarbons, fatty and aromatic acids, amino acids, porphyrins, purine and pyrimidine bases, and optically active lipids have been described from Orgueil as well as partially mineralized microstructures (organized elements). Most of these reports await independent confirmations. The origin of the Orgueil organic matter, the organized elements, and the petrogenesis is not yet known with a sufficient degree of certainty, but it is generally accepted that part of the complex organic matter is indigeneous. It has been suggested (Urey, 1962, 1965) that the Orgueil meteorite might be a lunar rock fragment representing the primeval lunar inorganic matrix which became contaminated with complex terrestrial organic matter during the violent processes that must have accompanied the capture (or escape) of the moon by the earth.