Smoky Quartz
Quartz var. Smoky Quartz · Semi-Precious Gemstone
Crystal System
Trigonal, typically forming prismatic crystals, though this specimen is a tumbled and polished stone with a massive, rounded habit.
Mineral Group
Silicates (Tectosilicates)
Chemical Formula
SiO2
Formation Process
Forms primarily through igneous and hydrothermal processes, where natural irradiation from surrounding radioactive rocks interacts with silicon dioxide over long periods.
About This Crystal
This is a tumbled, polished specimen of smoky quartz with a smooth, rounded shape. It displays a translucent to semi-transparent greyish-brown to smoky grey body color, with a vitreous to waxy luster typical of polished quartz, and subtle internal cloudiness and fractures.
Physical Characteristics
Color ranges from light grey to dark brown; white streak; no cleavage; conchoidal fracture; specific gravity of approximately 2.65; brittle tenacity; exhibits piezoelectricity.
Optical Properties
Uniaxial positive optical character; refractive index of 1.544 to 1.553; birefringence of 0.009; typically exhibits weak dichroism in brownish shades.
Hardness & Durability
Origin Region
Found globally with notable deposits in Brazil, Madagascar, the United States (Colorado), and Switzerland. Forms in pegmatites and hydrothermal veins.
Hardness & Durability
Mohs hardness of 7, making it durable for daily wear in jewelry; good toughness, though it can break along internal fractures if subjected to sharp impacts.
Care & Maintenance
Easy to care for; can be cleaned with warm soapy water and a soft brush. Avoid harsh chemicals and prolonged exposure to direct sunlight to prevent color fading.
Rarity & Value
Common; widely available and affordable, though exceptionally dark or flawless natural specimens can command higher collector values.
Special Characteristics
Natural irradiation centers create the characteristic smoky coloration. Can occasionally exhibit rutile or tourmaline needle inclusions.
Lore & History
Historically used by ancient cultures such as the Scottish and Chinese for ornamental objects and protective amulets. In modern crystal healing, it is associated with grounding, protection, and the Root Chakra.