Results are presented for 26 to 30 trace elements determined in four rock reference materials of geochemical interest: USGS Basalt BHVO‐1, Rhyolite Obsidian NIST 278, Basalt NIST688, and Phosphate Rock NIST694. Determinations were made by inductively coupled plasma mass spectrometry (ICP‐MS). Good agreement was obtained among solution standard comparison and standard addition analytical techniques, and among samples prepared with different dissolution methods. Generally good agreement was obtained between determined trace element values and values reported in the literat