This black tektite from China is in the impactite family. Tektites are fragments of molten rock that were ejected from a crater during a meteorite impact, cooling rapidly as they flew through the air, landing at varying distances from the crater. The impact would have caused the rock to be vitrified, ejected, and cooled rapidly, which explains the potential to mistake it for obsidian. However, each piece of tektite has a different make up. It can contain varying quantities of "cosmic" elements: nickel, platinum, iridium, cobalt, etc. Of course, these elements are also found on our planet. Significant quantities exist in planetary nuclei but are also found in trace quantities on the earth's crust. This fact allows us to identify tektites.