Seen this clump at an auction, and it is supposed to be pyrite, but just wondering if it might be something else. Supposedly, it came from the island of Elbe, of the coast of Italy. Its heavy, magnet sticks to it. Can anyone say for certain, what it is?
My first thought was Silver/Cobalt, but that's only a guess. https://www.mineralauctions.com/auc...r-in-silver-cobalt-ex-durkos-hauck-35401.html To me it does lead me to think it is a high-grade mineral specimen of some kind and it will do you better to have it looked at in person by a mineralogist. I'd be just guessing til the end of time as to what you have from just a photo online. It's pretty cool, what ever it is and worth something to mineral specimen collectors IMO, because it's got a lot going on with it.
Thanks for your reply. Its still at the auction house, and I cant do any testing, since it isnt mine. They want about $100 for it, so I dont want to buy out of curiosity, but it is interesting.
I didnt measure it, but yeah, about 10in. Although in the pic, it may look like quartz, but in real life, it seems to be all the same, just different size and shape crystals. May have to buy it next week.