Dumortierite Quartz
Dumortierite in Quartz (Aluminum Boro-Silicate Oxide) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Orthorhombic (Dumortierite inclusions) in a Hexagonal/Trigonal system (Quartz host); typically found in massive or fibrous habits.
Mineral Group
Silicates (Nesosilicates subgroup for Dumortierite; Tectosilicates for Quartz)
Chemical Formula
Al7(SiO4)3(BO3)O3 (Dumortierite) embedded within SiO2 (Quartz)
Formation Process
Metamorphic or Hydrothermal; forms when boron-rich fluids interact with aluminum-rich minerals in high-pressure metamorphic environments or pegmatites.
About This Crystal
An opaque to translucent denim-blue stone with a waxy to vitreous luster. This heart-shaped specimen displays a mottled 'denim' appearance where blue dumortierite fibers are densely packed within a quartz matrix, interspersed with brownish-grey host rock or feldspar inclusions.
Physical Characteristics
Color: Denim blue, violet-blue, or grayish-blue. Streak: White. Cleavage: Poor/None visible in massive form. Fracture: Conchoidal to uneven. Specific Gravity: 2.65 - 3.41. Fluorescence: Usually inert but can show weak blue or red under LWUV.
Optical Properties
Refractive Index: 1.544 - 1.686. Birefringence: 0.009 - 0.037. Pleochroism: Strongly pleochroic in individual crystals (red, blue, violet), but not visible in this massive polished form.
Hardness & Durability
Origin Region
Madagascar, Brazil, South Africa, and the United States (California/Nevada). Usually found in aluminum-rich regional metamorphic rocks.
Hardness & Durability
Mohs Hardness: 7 to 8.5 (Dumortierite is 7-8.5, Quartz is 7). Excellent durability and toughness, making it highly suitable for jewelry and carvings.
Care & Maintenance
Clean with warm soapy water and a soft cloth. Avoid harsh chemicals and ultrasonic cleaners if the stone has significant fractures. Generally stable under sunlight and temperature changes.
Rarity & Value
Relatively common in massive form; higher value is placed on specimens with intense, uniform 'denim' blue or rare transparent quartz crystals containing distinct blue needles.
Special Characteristics
Known for its distinct 'denim' blue color which is caused by charge transfers between iron and titanium within the dumortierite structure.
Lore & History
Named after French paleontologist Eugène Dumortier. It is historically used in ceramics and insulators. In metaphysical lore, it is known as the 'Stone of Patience' and is associated with the Third Eye chakra, believed to enhance mental discipline and organizational skills.