Science / Geology / Quartz: One of the most abundant minerals in the earth's crust. Has a chemical composition of SiO2 and a hardness of seven. One of the index minerals in Moh's Hardness Scale. Occurs in sedimentary, metamorphic and igneous rocks.

Quartz Arenite

Science / Geology / Quartz Arenite: A sandstone containing very little except pure quartz grains and cement. MORE


Science / Geology / Quartzite: (1) A very hard, clean, white metamorphic rock formed from a quartz arenite sandstone. (2) A quartz arenite containing so much cement that it resembles ( 1 ). MORE

Quartzose Sandstone

Science / Geology / Quartzose Sandstone: (1) A quartz arenite. (2) A clean quartz sandstone, less pure than a quartz arenite, that may contain a moderate amount of other detrital minerals and/or calcite cement. MORE


Science / Geology / Quartzose: An adjective used in reference to a rock that is composted primarily of quartz. MORE

Quartz-Iodine Lamp

Entertainment / Photography / Quartz-Iodine Lamp: Compact tungsten filament lamp designed to maintain its color temperature and light intensity throughout its working life. MORE


Science / Geology / Gabbro: A black, coarse-grained intrusive igneous rock that is the compositional equivalent of basalt. Composed of calcium-rich feldspars, pyroxene and possibly olivine, but containing little if any quartz. P MORE