Moldavites, a type of tektite, has a Mohs hardness of 5. 5-6. 0 and a specific gravity 2. 35, and consists mostly of silica. Caused by Meteorite impacts, creating glass from the heat and pressure. They are found and collected in the Czech Republic or areas close by. They are used for jewelry, or as specimens. Only have five left. $80.00 each. Approx. 3/4" to 1 1/2" long {SOLD}