1) Monoclinic mineral 
Moganite is a silicate mineral with the chemical formula SiO2 (silicon dioxide) that was discovered in 1984. It crystallises in the monoclinic crystal system. Moganite is considered a polymorph of quartz: it has the same chemical composition as quartz, but a different crystal structure. In 1994, the International Mineralogical Association (IMA) ha...