The moldavites belong to tektites. It means they
were formed in (or better to say “just before”)
a meteorite impact. If a meteorite hits
the ground at a place with porous
rock rich in silica, the material
is melted and turned into
a glassy substance.
Occasionally, the liquid melt can be ejected (in fact splashed
in flying masses) hundreds or even thousands of kilometers
away from the crater. Bits of the molten material
then solidify while still airborne,or immediately
after they fall on the ground. This happened
in Europe approx. 15 million years ago.
Tektites generally and moldavites particularly
are typical of pits, chutes, furrows and other features
sculptured on their surfaces. Such sculpturing can be attributed
to slow and uneven dissolution of the stone’s surface by ground
water seeping slowly through the rock wherein the stone is deposited.
99 % of all moldavite finds have provided
the South Bohemian localities, 1% were found
in South Moravian localities, tens of pieces were found
in the Lusatian area (near Dresden, recently even few pieces
in Poland), Cheb basin area (West Bohemia) and Northern Austria (Waldviertel, near Radessen)