I have this opal I was thinking about making in to a ring or pendant it's 15 mm long 12 mm long 5 mm think but not sure if its worth anything cheers
Imo black opal is way better than other types. Is it a straight opal or a doublet/triplet? Opals are mainly worth what someone wants to pay. There is no spot price for example. That said, I'm no expert but from the photo the colour looks strong and if you like it, and the person who may wear it likes opals then go ahead. It is fairly small and I'm guessing a doublet or triplet so I don't see it making you rich. I have a few opals but the wife doesn't like them so they just sit there.
Black opal is worth a fortune. Don't get suckered into a cheap offer and...do your home-work...shop around. H
this is the best summary on the net: http://www.opalsdownunder.com.au/learn-about-opals/introductory/how-opal-valued there are a lot of factors involved in grading opal. Just because the body is black, does not mean it is valuable.