obsidian punika kaca vulkanik alami kawangun minangka rock igneous extrusive. diprodhuksi nalika lahar felsic extruded saka gunung mbledhos ndingin kanthi cepet karo wutah kristal minimal 0
saka obsidianus latin, misprint saka obsianus (lapis) (watu) saka obsius 0
awet rock, medium atose rock 0