So I have this cigar tube lot. I purchased it in the late 80's at the Tucson Gem Show. There are approximately 27 in the tube - they have been stored in the glass tube in water ever since. I never did use them in a project. They came from Australia - they are about 1/2 and 1/2 carnelian and opal white cabochon.
The sizes vary (please see pictures) from just over an inch to small under 1/2". Some are really pretty some not so much. Some are flat backs some are rounds.
They will ship in this glass tube as this was the condition I purchased them in so perhaps it's important. I think opals dry out? It's the only mixed tube of opals and carnelians I have. I think they are nicer than the pictures but that's just my opinion. I certainly am not an expert in these matters.