a white or colorless vitreous insoluble solid (SiO2); various forms occur widely in the earth's crust as quartz or cristobalite or tridymite or lechatelierite
cristobalite 1
noundomain: substance
Princeton WordNet [ver.3.1]
English
Definition
a white mineral consisting of silica; found in volcanic rocks
a white or colorless vitreous insoluble solid (SiO2); various forms occur widely in the earth's crust as quartz or cristobalite or tridymite or lechatelierite