Blue Quartz (specifically Dumortierite Quartz)
Quartz with inclusions of Dumortierite · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal (Quartz host); The tumbled habit seen here is massive or microcrystalline, with no distinct crystal faces.
Mineral Group
Silicates (Tectosilicate host with Nesosilicate inclusions)
Chemical Formula
SiO2 (Quartz) with Al7(BO3)(SiO4)3O3 (Dumortierite inclusions)
Formation Process
Metamorphic or Hydrothermal; forms when quartz crystallizes or recrystallizes in the presence of Dumortierite fibers, which impart the blue color.
About This Crystal
A dense, opaque to translucent stone with a denim-to-royal blue color. The color is typically uneven or mottled due to the fibrous nature of the inclusions. It exhibits a vitreous to waxy luster when polished.
Physical Characteristics
Color: Blue to violet-blue; Streak: White; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65–2.90; Fluorescence: Generally inert to weak blue or green under UV.
Optical Properties
Refractive Index: 1.544–1.553; Doubly refractive; No distinct optical phenomena like asterism, but may show slight pleochroism in individual inclusions.
Hardness & Durability
Origin Region
Notably sourced from Brazil, South Africa, Madagascar, and the USA (California and Virginia). Found in aluminum-rich metamorphic rocks.
Hardness & Durability
Mohs Hardness: 7 (Quartz host) to 8.5 (Dumortierite inclusions); very durable and suitable for daily jewelry wear.
Care & Maintenance
Clean with warm soapy water and a soft brush; safe for ultrasonic cleaning but avoid harsh chemicals and extreme heat.
Rarity & Value
Common and affordable; value is determined by the intensity and uniformity of the blue color and the size of the specimen.
Special Characteristics
Features a 'denim' look caused by fibrous blue mineral inclusions within a quartz matrix; lacks the pyrite flecks seen in Lapis Lazuli.
Lore & History
Historically used as a 'Stone of Order' and 'Stone of Patience.' Traditionally associated with the Throat and Third Eye chakras, believed to enhance mental discipline and organizational abilities.