Mineral Family: Garnet Group

Chemical Composition: (Al,Fe)7(BO3)(SiO4)3O3
Cleavage: Distinct, Imperfect
Color: Blue-black, Pink-red, brown, green
Crystal System: Orthorhombic
Form/Habit: Fiberous aggregates
Fracture: Uneven, brittle
Gravity: 3.2-3.4
Hardness: 7-8
Luminescence: Yellowish-white (long wave) / Blueish-white (short wave)
Luster: Vitreous
Streak: White, blueish-white
Transparency: Transparent to opaque

Where does Dumortierite come from?

Dumortierite Placeholder
Dumortierite

Dumortierite deposits have been found in Austria, Botswana, Brazil, California, Canada, Czech Republic, France, Germany, India, Italy, Japan, Kazakhstan, Madagascar, Mozambique, Namibia, Norway, Peru, Slovakia, South Africa, Sri Lanka, Sweden and the United States (Arizona, Colorado, Montana, New Mexico, Nevada)

What is Dumortierite?

Dumortierite belongs to the Silicate family. Silicate minerals form the largest family of minerals, including more than 25% of all known minerals and 40% of all common minerals. In addition to being a major part of the Earth’s crust, Silicate minerals have also been found on the moon and in meteorites. Silicates are minerals which contain the elements Silicon (a light gray shiny metal) and Oxygen (a colorless gas). Together, these two elements form a tetrahedron – a shape similar to a pyramid – with a Silicon atom in the center and Oxygen atoms at each of the four corners. These tetrahedra connect with other chemical structures, in six different ways, to form various minerals and rocks. There are six main groups of Silicate minerals, and these main groups are further subdivided into secondary subdivisions, such as Quartz and Feldspar. Dumortierite is in the Nesosilicate family, which have isolated tetrahedra, (tetrahedra which are not connected to each other). Other Nesosilicates include the entire Garnet family, Kyanite, Peridot and Topaz.

How is Dumortierite formed?

Dumortierite is typically formed in aluminum-rich metamorphic rocks, created by contact metamorphism. Dumortierite is occasionally found in boron-rich igneous rocks.

Where is Dumortierite mined?

Dumortierite is a secondary mineral found in aluminum-ore mines and garnet mines. It is used in manufacturing high-grade porcelain and ceramics, as well as an ornamental stone.

Dumortierite Enhancements

All Dumortierites may be considered fully natural, enhanced only by tumbling, cutting, or polishing.