Dumortierite in Quartz
Quartz var. Dumortierite Quartz · Mineral Specimen and Decorative Stone
Crystal System
Trigonal crystal system, massive or crystalline quartz matrix containing fibrous or needle-like inclusions of dumortierite
Mineral Group
Silicates, specifically Tectosilicates (Quartz) and Nesosilicates (Dumortierite)
Chemical Formula
SiO2 with inclusions of Al7BO3(SiO4)3O3
Formation Process
Hydrothermal and pegmatitic processes where aluminum borosilicate minerals form within quartz veins or pegmatite pockets under moderate to high temperature and pressure
About This Crystal
An elongated, water-worn or rough pebble-shaped specimen of milky-to-white quartz featuring a prominent, striking streak of dark blue to purplish-blue dumortierite inclusions running lengthwise through the matrix. The quartz is translucent to opaque with a vitreous to waxy luster on its worn exterior surfaces
Physical Characteristics
Color ranges from white and translucent gray in the host quartz to deep denim-blue or violet-blue in the inclusion zone. The streak is white. Cleavage is indistinct in quartz, specific gravity is approximately 2.65, tenacity is brittle, and the fracture is sub-conchoidal to uneven
Optical Properties
Singly or doubly refractive depending on the quartz orientation with a refractive index of approximately 1.544 to 1.553. Birefringence is 0.009. Displays no strong pleochroism in the quartz matrix itself, though the blue inclusions can show slight pleochroism under microscopic examination
Hardness & Durability
Origin Region
Found worldwide including Brazil, Madagascar, Namibia, and the USA (Colorado and Nevada)
Hardness & Durability
Mohs hardness of 7 for the quartz host, making it quite durable for handling, though the included areas can slightly alter local toughness depending on the concentration of fibers
Care & Maintenance
Can be safely cleaned with warm soapy water and a soft brush. Avoid harsh chemical cleaners, prolonged direct sunlight to prevent any minor matrix changes, and store separately from softer stones to avoid scratching
Rarity & Value
Common to uncommon depending on the richness and vibrancy of the blue inclusion color. Prices are generally affordable for tumbling rough and raw mineral specimens, scaling up with high contrast and intense blue color concentration
Special Characteristics
Notable for the fibrous, dense patches of rich blue dumortierite trapped as inclusions inside a milky quartz host, creating a vivid color contrast
Lore & History
Often referred to as the stone of patience and mental discipline in modern crystal healing circles. Associated with the throat and third-eye chakras, believed by practitioners to enhance organizational abilities and foster calmness, though these are traditional non-scientific beliefs