Clear Quartz (Rock Crystal)
Quartz var. Rock Crystal · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Trigonal symmetry; typically appears as hexagonal prisms with pyramidal terminations; massive or tumbled habit in this specimen
Mineral Group
Silicates (Tectosilicate)
Chemical Formula
SiO2
Formation Process
Primarily Hydrothermal (crystallizing from silica-rich fluids in veins or cavities) or Igneous (pegmatitic)
About This Crystal
A tumbled, colorless, and transparent to translucent specimen of macrocrystalline quartz. It exhibits a vitreous (glassy) luster with internal fractures and cloudiness characteristic of natural rock crystal.
Physical Characteristics
Color: Colorless; Streak: White; Cleavage: None/Poor; Fracture: Conchoidal; Specific Gravity: 2.65; Fluorescence: Generally inert
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Optical Character: Uniaxial positive; Dispersion: 0.013
Hardness & Durability
Origin Region
Found globally; major sources include Minas Gerais (Brazil), Arkansas (USA), and Madagascar
Hardness & Durability
Mohs Hardness: 7; Toughness: Good; Highly stable and durable for all types of jewelry use
Care & Maintenance
Safe to clean with warm soapy water, ultrasonic cleaners, or steam. Extremely durable, but should be stored away from harder stones like Topaz or Diamonds.
Rarity & Value
Common; Value is determined by clarity and size. Massive/tumbled pieces are very affordable, while large eye-clean museum crystals are more valuable.
Special Characteristics
Piezoelectric and pyroelectric properties. May contain internal 'rainbow' veining due to light interference in conchoidal fractures.
Lore & History
Historically known as 'Krystallos' (frozen ice) by Greeks. Symbolically associated with clarity and the Crown Chakra; historically used for divinatory crystal balls and decorative carvings.