Dumortierite Quartz
Quartz var. Dumortierite Quartz · Semi-Precious Gemstone / Ornamental Stone
Crystal System
Trigonal, massive or tumbled habit
Mineral Group
Silicates, Tectosilicate subgroup
Chemical Formula
SiO2 with Al7BO3(SiO4)3O3 inclusions
Formation Process
Hydrothermal and metamorphic processes where aluminum borosilicate infiltrates and crystallizes within host quartz veins.
About This Crystal
A polished, tumbled stone showing patches of vivid denim-to-royal blue dumortierite inclusions intergrown with white to translucent milky quartz, creating a mottled or patchy pattern.
Physical Characteristics
Colors range from white and translucent to deep blue. Vitreous to waxy luster when polished. Conchoidal fracture, no distinct cleavage in the quartz matrix. Specific gravity is approximately 2.65.
Optical Properties
Singly refractive to uniaxial positive for the quartz host, with a refractive index around 1.544 to 1.553. Non-pleochroic in the quartz areas, but the blue inclusions can show pleochroism.
Hardness & Durability
Origin Region
Madagascar, Brazil, Namibia, France, and the USA
Hardness & Durability
Mohs hardness is 7 for the quartz host, making it durable for general jewelry use and resistant to scratching.
Care & Maintenance
Clean with warm soapy water and a soft cloth. Avoid harsh chemicals and prolonged direct sunlight to prevent any surface dulling.
Rarity & Value
Common to uncommon. Value depends heavily on the intensity and distribution of the blue color within the quartz matrix. Typically affordable as tumbled stones and cabochons.
Special Characteristics
Features striking fibrous or patchy blue inclusions of dumortierite locked inside a durable quartz host, providing a unique mosaic appearance.
Lore & History
Often associated with the throat and third-eye chakras in modern crystal healing traditions, believed to enhance patience, mental discipline, and organizational skills. These are traditional beliefs and not scientifically proven.