I think you are right Fairycrystal about being careful, not all sellers are very knowledgeable, and I think most " scams " come down to a seller maybe mislabeling a product. I don't think there is many real scams out there anymore, at least in terms of fake crystals. In my experience some sellers are really great and know their stuff, and others do not. I suppose it's the same with real metaphysical shops as well.
From all my dealings with ebay I have found the mass majority of sellers to be quite honest and most will give you honest answers if you talk to them. Fairycrystal you are lucky if you have a real metaphysical shop that you trust.
I have several around here, but I think they get their stuff online too
I am currently dealing with several sellers from Thailand and india, buying a tourmaline gem for a ring, and you would be surprised how many of them actually care about me being satisfied, and taking my time picking out a gem. They have all been upfront and honest about any flaws or imperfections, sending me extra videos and pictures. And this is a product around 500-2000 dollars, so it's good money for them. None of them seem like they care about the money over my happiness. I have been quite impressed actually.
Most of them have even offered 100 % refund if I don't like it for any reason.