How to cut fire obsidian?

realrockhound is correct, the original images you posted are fracture fire, just the prismatic effect from the fracture and it will disappear as you grind around on it (or the piece will just break into pieces altogether).  The other piece you posted is technically gold sheen, but it often has layers of lower grade fire in it, mixed with the gold sheen and mahogany - still very cool stuff.

As some have alluded to, the layers are very thin.  In my experience, the really good stuff has white/blue-ish lines, but some times the yellow ribbon and red ribbon stuff can be very hot.  If the layers are gray-ish or not very defined, it could be low grade fire, but typically isn't worth chasing too far in my opinion (except as a practice piece)

You never know what you're going to run into.  The layers can be crazy and flowing all over the place, and other times you get lucky and they're mostly flat and spaced apart.  The stuff can make you pull your hair out, but the reward you get from a good chunk keeps me chasing

Here are a couple of examples, one with crazy layers all over, and another with flat white-ish/blue-ish layers, just as a reference.  It's tough to throw this stuff into a regular slab saw, there's usually not enough space between layers for a blade to fit and you'll likely kill something beautiful lol.  Most of the time I use a Gryphon glass band saw to isolate layers, but even then it's tough to thread the blade between layers and swearing soon follows.

Have fun with it!


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