1.2" Dumortierite in Quartz - Vaca Morta Quarry, Brazil

Dumortierite is an aluminum boro-silicate mineral that often forms as fibrous aggregations. The crystals are typically blue, however grey-blue, green, and brown crystals are also common. In rare cases, the crystals can be violet or pink. Dumortierite is often found as fibrous crystals within massive quartz: blue dumortierite-included quartz, known as "dumortierite quartz" crystals, are highly sought after.

About Quartz

Quartz is the name given to silicon dioxide (SiO2) and is the second most abundant mineral in the Earth's crust. Quartz crystals generally grow in silica-rich environments--usually igneous rocks or hydrothermal environments like geothermal waters--at temperatures between 100°C and 450°C, and usually under very high pressure. In either case, crystals will precipitate as temperatures cool, just as ice gradually forms when water freezes. Quartz veins are formed when open fissures are filled with hot water during the closing stages of mountain formation: these veins can be hundreds of millions of years old.