Moldavite
Moldavite (Tektite) · Collector Mineral / Semi-Precious Gemstone
Crystal System
Amorphous (No crystal system; non-crystalline natural glass)
Mineral Group
Tektite (Natural Glass class)
Chemical Formula
SiO2 + Al2O3 (Silica glass with aluminum, potassium, and iron oxides)
Formation Process
Meteoritic Impact (Extraterrestrial impact on terrestrial silica-rich sediments approximately 14.7 million years ago)
About This Crystal
A translucent to opaque olive-green or forest-green natural glass. This specimen shows characteristic 'sculpting' or etched pitting on the surface. It possesses a vitreous luster and frequently contains unique gas bubbles or Lechatelierite (melted silica) inclusions.
Physical Characteristics
Color: Bottle green to olive; Streak: White; Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.32–2.40; Fluorescence: None; Tenacity: Brittle.
Optical Properties
Isotropic (Singly refractive); Refractive Index: 1.48–1.54; Birefringence: None; No pleochroism or dispersion.
Hardness & Durability
Origin Region
Bohemian plateau, Czech Republic (specifically the Vltava River basin)
Hardness & Durability
Mohs Hardness: 5.5 to 7.0; Toughness: Low/Fragile; Sensitive to sudden temperature changes and hard impacts.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners and steam cleaning. Store separately to prevent scratching from harder minerals like quartz or beryl.
Rarity & Value
Very Rare; Found only in a localized strewn field in Central Europe. Value is high and dictated by weight (grams), texture, and translucency. Frequently counterfeited with green bottle glass.
Special Characteristics
Pitted/etched surface texture (sculpting); elongated gas bubbles and high-silica glass wires (Lechatelierite) visible under magnification.
Lore & History
Historically used as amulets in the Neolithic period. Symbolized 'the Grail stone' in medieval lore. In modern metaphysical circles, it is associated with rapid spiritual transformation and the Heart Chakra.