History · Geology
About Bohemia / Moldau River Strewn Field
The Bohemia / Moldau strewn field in southern Czech Republic is the unique world locality for moldavite — the deep forest-green tektite (impact glass) formed during the Ries Crater impact ~14.7 million years ago. The strewn field extends from southern Bohemia (Český Krumlov, Třebíč) into Moravia.
Geology
Moldavite formed when a meteorite impact in present-day Bavaria (Ries Crater, ~24 km diameter) ejected molten silica-rich crustal melt. The vapor-and-spray ballistic distribution carried molten droplets ~400 km eastward to the present strewn field, where they cooled in flight and solidified as glass before landfall.
Notable Minerals
Moldavite (forest-green to olive-green tektite glass with characteristic corroded “sculpted” surface texture). Pieces typically weigh 1-30 g; museum-grade specimens up to 200+ g exist. Distinct from other tektite types (australites, indochinites, etc.) by color and chemistry.
Collector Notes
Czech moldavite mining is permit-controlled; export restrictions tighten supply. Many imitations exist (synthetic green glass, painted glass, plastic) — provenance and characteristic surface texture matter for authentication.
