How much do you think this opal is worth? I’ve been told it’s a Queensland bolder opal it has good color it’s 31cts and there is no sand or Boulder matrix on it at all. When I purchased it it was already cut and horribly polished so I made it more symmetrical and round and gave it a good polish
It largely depends on what market that you are in. Here in Queensland opals like that will sell for about $20 because they are plentiful. However, in other countries where the opal does not occur, prices of $100+ are likely.
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I would agree with the last statment! 
So you live in Queensland and you see opals like this all the time so you’re positive it is a Queensland opal? I haven’t been able to find anything like it at in the US I only found out it was a Queensland boulder opal because of the forms all the border opal I have and have seen is normally attached to sand matrix. I believe the only type of opals I’ve gotten out of Queensland have been the Yawhwa thin vain opal it’s definitely one of my favorite types of opals the one in the picture is the type I’m talking about I just cut this last week .
Well that sucks I really thought it would be a lot more valuable than that specially since there’s no Boulder matrix attached to like most border opal. Being 31 carats of pure opal like you can see in the original pictures I can shine a light straight through. I bought gold to make it into a bezel that’s why I was asking what it would be worth since I have nothing to compare it with but I don’t think I want to waste the gold you guys think it’s just some common opal than I should use the gold on something more valuable.
Boulder opal can take many forms but the common part is that they all form in ironstone rock. The rock varies from a fine grained mudstone through sandstone and conglomerate, the quality of the rock varies from chalky and friable through to fairly strong. The opal occurs as infill in cracks and pores in the rock, different fields can have different and unique styles. Fairy opal (typically from Opalton) is opal as a pore fill in sandstone similar to Andamooka, and is usually treated to darken the matrix. Then metrix opal is generally thin veins of opal in iron stone that is cut so that the matrix and thin veins show, these are typical of Yowah, Koroit and Duck Creek. Pipe opal is where the opal is a couple of mm thick and the stone is cut with the opal face and ironstone back, this occurs in all fields especially Opalton. Finally the opal can be thick enough to cut as a solid stone, this can occur in any field, and as always the material may vary between potch and full brilliant colour.
To give you an idea of the relative cost and availability of the material here a friend cuts the stuff into spheres. This one is 3.9kg (about 8.6lb). boulder opal sphere — Sphere Art Australia
When photographing opal try to use natural light or ambient high crt light as normal phone flashes result is washed out photos. The first photo may not look great due to the photo rather than the stone.
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Thank you very much that is very insightful I appreciate all of the information and the fact that you were willing to spend the time to share it with me I am absolutely and opal addict it’s amazing to see the difference in prices since you guys have the ability to be their source it yourself or a direct line to the miners and most likely action I’m the best rough I have had a really hard time trying to photograph opal my best have come from outside I hate you the fact it’s so hard and the actual over a photo and so many people use filters that misleading but natural light is not always available. So once again thank you also the picture of that sphere on this stand is absolutely amazing I wish I could see it in person to see all the color not that I could afford it