Of which common mineral is rock crystal a variety
Mineral the various species, which were determined by the mineral's geological environment when formed. Changes in the temperature, pressure, or bulk composition of a rock mass cause changes in its minerals. Within a mineral species there may be variation in physical properties or minor amounts of impurities that are recognized by mineralogists or wider society as a mineral "variety", for example amethyst, a purple variety of the mineral species quartz. Minerals can be described by their various physical properties, which are related to their chemical structure and composition. Common distinguishing characteristics include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak,
Mineral Mineral A mineral is a naturally occurring chemical compound, usually of crystalline form and not produced by life processes. A mineral has one specific chemical composition, whereas a rock can be an aggregate of different minerals or mineraloids. The study of minerals is called mineralogy. Minerals are classified by variety, species, series and group, in order of increasing generality. As of November 2018, there are more than 5,500 known mineral "species"; 5,389 of these have been approved by the International Mineralogical Association (IMA). Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish