Dumortierite Quartz
Quartz var. Dumortierite in Quartz · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal (Quartz host), Orthorhombic (Dumortierite inclusions); tumbled smooth habit
Mineral Group
Silicates (Tectosilicate host with Nesosilicate inclusions)
Chemical Formula
SiO2 with inclusions of Al7BO3(SiO4)3O3
Formation Process
Metamorphic and pegmatitic processes where aluminium-rich borosilicate minerals crystallize alongside or become included within growing hydrothermal quartz veins.
About This Crystal
A small, tumbled, and polished smooth specimen featuring a mix of deep denim blue, indigo, and greyish translucent areas. The surface is smooth and shiny with vitreous to waxy luster, displaying characteristic internal fibrous inclusions of dumortierite creating cloudy patches and streaks of blue color.
Physical Characteristics
Color ranges from deep indigo blue to greyish-blue; white to colorless streak; conchoidal fracture; no distinct cleavage visible on the tumbled surface; specific gravity approximately 2.65 for the quartz host; brittle tenacity.
Optical Properties
Uniaxial positive (Quartz host); refractive index around 1.544-1.553; typically translucent to opaque due to dense needle-like inclusions; lacks strong chatoyancy in this tumbled piece but shows internal color zoning.
Hardness & Durability
Origin Region
Brazil, Madagascar, Namibia, USA; found in metamorphic and pegmatitic environments
Hardness & Durability
Mohs hardness of 7 for the quartz host, making it durable for daily jewelry wear, though the included areas can occasionally present micro-fracture zones.
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals, ultrasonic cleaners, and prolonged exposure to direct sunlight to preserve surface polish.
Rarity & Value
Uncommon to rare depending on the intensity and distribution of the blue dumortierite color saturation; generally affordable as tumbled stones, highly prized when in massive high-grade rough or intense blue quartz formations.
Special Characteristics
Contains natural fibrous or acicular inclusions of the mineral dumortierite trapped inside a clear-to-milky quartz matrix, creating a striking denim-blue visual effect.
Lore & History
Often referred to as the Stone of Patience and mental discipline in modern crystal healing traditions. Associated traditionally with the throat and third eye chakras, believed to enhance focus, communication, and orderly thought.