Grey Quartz
Quartz (Silicate Mineral) · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal; typically hexaganol prisms with rhombohedral terminations, but masive in this specimen
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2
Formation Process
Primarily Magmatic or Hydrothermal; forms in pegmatites, veins, and volcanic cavities as magma cools or mineral-rich water precipitates
About This Crystal
A translucent to opaque grey stone with a vitreous to waxy luster. It exhibits some internal cloudiness and visible dark speck inclusions, carved into a crescent moon shape with a polished surface.
Physical Characteristics
Color: Grey; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Usually inert but can show weak green or yellow under UV if certain trace elements are present.
Optical Properties
Refractive Index: 1.544-1.553; Birefringence: 0.009; Doubly refractive; No specific phenomena like labradorescence or opalescence visible.
Hardness & Durability
Origin Region
Worldwide; notably Brazil, USA, Madagascar, and India
Hardness & Durability
Mohs Hardness: 7; Toughness: Fair to Good; Very stable and suitable for daily jewelry wear.
Care & Maintenance
Clean with warm soapy water and a soft brush; safe for ultrasonic cleaners. Avoid harsh chemicals and sudden temperature shifts.
Rarity & Value
Common; value is generally low for massive grey quartz, determined primarily by the quality of the carving and polish.
Special Characteristics
Features internal veining and dark particulate inclusions (likely iron oxides or carbonaceous material) that give it a 'cloudy' or 'stormy' appearance.
Lore & History
Quartz has been used since antiquity for tools and talismans. Grey quartz is often associated with grounding, emotional stability, and the 'root' or 'earth' energy in contemporary crystal lore.