Moldavite

Moldavite is a tektite — a natural impact glass formed when a meteorite struck Earth ~14.7 million years ago, melting and ejecting silica-rich crustal material across central Europe. The deep forest-green color and distinctive textured surface make moldavite the most visually distinctive of all tektites.

Properties

• Formula: SiO₂ + Al₂O₃ + alkali oxides (impact-melted crustal glass)
• Crystal system: Amorphous (impact glass)
• Hardness: 5.5 – 7
• Color: Forest-green, olive-green, occasionally brownish-green
• Streak: White
• Luster: Vitreous
• Cleavage: None (conchoidal fracture)
• Density: 2.3 – 2.4 g/cm³

Occurrence

Restricted to a strewn field across southern Bohemia and Moravia (Czech Republic) and small parts of Austria/Germany. The parent impact crater is the Ries Crater (Bavaria). Pieces are typically small (1-30 g) and surface-textured by sculpting during atmospheric flight.

Identification

Forest-green glass + distinctive corroded/sculpted surface texture + Czech locality. Distinguish from obsidian (typically black, no impact origin), Libyan desert glass (yellow, different impact event) and synthetic green glass (uniform smooth surface).

Collector Notes

Faceted moldavite gems and natural sculpted “drops” are popular metaphysical and collector items. Czech regulators have restricted exports; market supply is constrained and many pieces are heat-treated or fake — provenance matters.