Fireworks Obsidian Slabs
Obsidian is volcanic glass. It often has flow lines that create interesting
effects. Gold sheen and silver sheen obsidians display gold and silver
chatoyance when polished, rainbow obsidian displays different colors,
etc. Obsidian has a reputation for being difficult to polish. Usually
the reason for difficult polishing is that coarse grits can create
a fairly deep fracture zone that doesn't come out when the stone is
cut at finer grits. Another problem is obsidian doesn't polish well
if it gets too hot. So, if you don't use super coarse grinding wheels
and if you keep your polishing wheel slow and wet, good results will
easily be obtained.
The surface of Fireworks Obsidian is a little crackly, but it isn't
that noticable because it takes a good polish. Cuts easily and polishes
well with cerium or tin oxide.
Example of Fireworks Obsidian Cabochon