Milk Quartz

Milky quartz is a common mineral that is found in many different types of rocks. The chemical formula is silicon oxide (SiO2). One type of quartz is easily identified by its hexagonal crystals, but quartz can also be found in a large mass. Quartz can be broken or weathered into the tiny pieces we know as sand. Quartz is a very hard mineral and in fact is the hardest of the common minerals. Quartz is number seven on the Mohs hardness scale. Quartz is also chemically stable, which means that it weathers very slowly.
Quartz can be colored yellow, milky white, rose, smoky (brown or black), and the best known of the colored crystals amethyst, which is purple. Impurities in the rock at the time of formation causes the quartz crystal to have these different colors.
Quartz is used by humans in producing optical instruments and electical devices. It is also used to make sandpaper and grinding tools.
Category:Minerals
Category:Everyday Objects
Category:Quartz