Quartzite
Metamorphic Quartzite (Quartz-dominant Rock) · Mineral Specimen / Decorative Stone / Industrial Mineral
Crystal System
Trigonal/Hexagonal; typically occurs in a massive, microcrystalline habit with a granoblastic texture.
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2 (Silicon Dioxide) with trace Al2O3, Fe2O3, and CaO
Formation Process
Metamorphic; forms from the recrystallization of quartz sandstone under high heat and pressure, causing sand grains to fuse into a solid network.
About This Crystal
A light tan to greyish, rounded cobble with a sugary, granular texture. It is opaque to dimly translucent on thin edges with a dull to sub-vitreous luster and visible weathering pits.
Physical Characteristics
Color: Tan/Beige; Streak: White; Cleavage: None; Fracture: Conchoidal to uneven; Specific Gravity: 2.6-2.7; Fluorescence: Generally inert.
Optical Properties
Refractive Index: ~1.544-1.553; Birefringence: 0.009; typically lacks significant optical phenomena in massive form due to its polycrystalline nature.
Hardness & Durability
Origin Region
Global; common in metamorphic belts such as the Appalachian Mountains, Alps, and Brazilian shields. Often found as river-worn cobbles.
Hardness & Durability
Mohs Hardness: 7; Extremely tough and durable; resistant to mechanical weathering and chemical erosion; excellent stability.
Care & Maintenance
Requires minimal care. Can be cleaned with warm soapy water and a soft brush. Resistant to most household chemicals but can be scratched by harder stones like topaz or sapphire.
Rarity & Value
Very Common; low monetary value as a specimen. Its value lies primarily in industrial use or lapidary landscaping. Untreated.
Special Characteristics
Granoblastic texture where original sand grain boundaries have disappeared; occasionally shows cross-bedding remnants from its parent sandstone.
Lore & History
Historically used for stone tools when flint was unavailable. In folklore, it is often associated with stability and endurance. In modern practices, it is viewed as a grounding stone for the Root Chakra.