Earth’s continental crust, behind feldspar.- Mean Girls (Wikipedia)
Mean Girls is a 2004 American teen comedy film directed by Mark Waters and written by Tina Fey. It stars Lindsay Lohan, Rachel McAdams, Tim Meadows, Ana Gasteyer, Amy Poehler, and Fey. The film follows Cady Heron (Lohan), a naïve teenager who transfers to an American high school after years of homeschooling in Africa. Heron quickly befriends two outcasts (Lizzy Caplan and Daniel Franzese), with the trio forming a plan to exact revenge on Regina George (McAdams), the leader of an envied clique known as the Plastics.
- Chalcedony (Wikipedia)
Chalcedony (/kælˈsɛdəni/ kal-SED-ə-nee, or /ˈkælsəˌdoʊni/ KAL-sə-doh-nee) is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. These are both silica minerals, but they differ in that quartz has a trigonal crystal structure, while moganite is monoclinic. Chalcedony’s standard chemical structure (based on the chemical structure of quartz) is SiO2 (silicon dioxide).
- Moganite (Wikipedia)
Moganite is an oxide mineral with the chemical formula SiO2 (silicon dioxide) that was discovered in 1976. It was initially described as a new form of silica from specimens found in the Barranco de Medio Almud, in the municipality of Mogán on the island of Gran Canaria, in the Canary Islands (Spain), receiving in a later work the name derived from this locality. In 1994 the International Mineralogical Association decided to disapprove it as a valid mineral, since it was considered indistinguishable from quartz. Subsequent studies allowed the IMA to rectify it in 1999, accepting it as a mineral species. It has the same chemical composition as quartz, but a different crystal structure.
- Flint (Wikipedia)
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start fires.