Number 83 (Story #4), June 8, 1992 by Phillip F. Schewe and Ben Stein THE MOST ABUNDANT MINERAL ON EARTH , silicate perovskite, has, ironically, been of more interest to materials scientists than to geologists, according to Alexandra Novrotsky of the Princeton Materials Institute. Perovskite, a class of ceramic crystal (e.g., MgSiO3) in which three chemical elements in the ratio 1:1:3 form a cubic structural unit, makes up 80 to 100% (by volume) of the lower mantle. Materials scientists eagerly study artificially made perovskite, hoping to synthesize, among other things, high-temperature superconductors. By contrast, the perovskite samples geologist want to study lie 670 km underfoot. Increasingly, however, geologists are able to study perovskites under conditions resembling those of deep Earth interior using high-pressure diamond-anvil cells. (Materials Research Society Bulletin, May 1992.)