Dumortierite Quartz
Quartz var. Dumortierite Included Quartz · Mineral Specimen and Semi-Precious Ornamental Stone
Crystal System
Trigonal, commonly shaped or cut into a cubic form with striated fibrous inclusions
Mineral Group
Silicates, specifically Tectosilicates
Chemical Formula
SiO2 (with Al7BO3(SiO4)3O3 inclusions)
Formation Process
Hydrothermal and metamorphic processes where aluminum borosilicate mineral fibers grow internally within host quartz crystals during crystallization
About This Crystal
The specimen is a distinct cubic shape featuring vibrant blue to periwinkle coloration with characteristic linear, fibrous inclusions running through a translucent to opaque quartz matrix. The surface shows distinct striations and a matte to vitreous luster.
Physical Characteristics
Blue body color with white patches, white streak, conchoidal to uneven fracture, specific gravity around 2.65 for the quartz host, brittle tenacity, and lack of significant fluorescence under UV light
Optical Properties
Uniaxial positive optical character, refractive index of approximately 1.544 to 1.553, doubly refractive, displaying no notable pleochroism in the host quartz but strong color depth from the dense internal fibers
Hardness & Durability
Origin Region
Notable sources include Madagascar, Brazil, Namibia, and the United States, typically found in metamorphic and pegmatitic environments
Hardness & Durability
Mohs hardness of 7 for the quartz host, making it durable for general handling, though the fibrous inclusions can introduce structural weaknesses; fair to good toughness
Care & Maintenance
Clean with warm soapy water and a soft brush; avoid harsh chemicals, ultrasonic cleaners, and prolonged exposure to direct sunlight to maintain the integrity of the stone
Rarity & Value
Uncommon to rare depending on the density and vividness of the blue coloration; valued among collectors and lapidary artists, with prices varying based on stone size, saturation, and cut quality
Special Characteristics
Notable for its striking natural denim-blue or indigo fibrous needle inclusions trapped entirely within a transparent-to-translucent quartz host, often cut into geometric shapes like cubes or spheres
Lore & History
Often associated in modern metaphysical practices with mental discipline, patience, and organizational focus, linked traditionally to the throat and third-eye chakras, though these are cultural interpretations rather than scientific attributes