Moldavite
Tektite var. Moldavite · Collector Mineral / Semi-Precious Gemstone (Meteoritic Material)
Crystal System
Amorphous (Non-crystalline). Often occurs as splash-like droplets, aerodynamically shaped discs, or irregular shards with a deeply pitted sculping texture.
Mineral Group
Tektite (Natural Silica Glass)
Chemical Formula
SiO2(+Al2O3) predominantly, with minor K2O, CaO, MgO, and FeO
Formation Process
Meteoritic impact (vltavines). Formed approximately 14.8 million years ago when an asteroid impact in southern Germany ejected molten terrestrial sediments that cooled in flight before landing in the Czech Republic.
About This Crystal
A translucent to transparent olive-green to forest-green natural glass. It features a unique, deeply etched or rugose surface caused by millions of years of chemical weathering in the soil. The interior is characterized by 'lechatelierite' (melted quartz wires) and elongated gas bubbles.
Physical Characteristics
Color: Forest green, olive green, or pale green. Streak: White. Cleavage: None. Fracture: Conchoidal (shell-like). Specific Gravity: 2.27–2.40. Luster: Vitreous (glassy). Usually shows no fluorescence.
Optical Properties
Refractive Index: 1.48–1.54 (Singly refractive). Birefringence: None. No pleochroism. Characterized by dense internal flow lines and 'gas bubbles' that are often elongated.
Hardness & Durability
Origin Region
Southern Bohemia and South Moravia, Czech Republic (Ries Crater impact event)
Hardness & Durability
Mohs Hardness: 5.5 to 7.0. Brittle tenacity; similar to man-made glass. It is sensitive to thermal shock and can be easily scratched by harder minerals like quartz or topaz.
Care & Maintenance
Avoid ultrasonic and steam cleaners. Clean with warm, soapy water and a soft cloth. Store separately from harder gemstones to prevent scratching. Avoid sudden temperature changes and hard impacts.
Rarity & Value
Very Rare. Limited geographic supply as it is only found in the Moldau River basin. Value factors include color, weight, and the complexity of the surface 'sculpting'. Heavily faked in the market using green bottle glass.
Special Characteristics
Lechatelierite inclusions (wires of fused silica) and vacuum-pressured gas bubbles. The specific 'ferny' or 'wormy' etching on the skin is highly diagnostic of authentic specimens.
Lore & History
Historically used as amulets in Neolithic times. Symbolically associated with the 'Heart Chakra' and rapid spiritual transformation. Traditionally known as the 'Emerald that fell from the sky' due to its extraterrestrial origin story.