Gemstones are a targeted market for conmen who want to sell fake products to innocent customers. You might have a difficult time differentiating between these fake and genuine crystals initially. After a few uses, the real quality begins to show, but it would be too late by then. Save yourself from this and only buy gemstones from authorized stores.
Request for a certificate of authenticity every time you shop for crystals or gemstones. This may save you a lot of money and help you get the right gemstone you desire. Shopping online is safer in some cases. You will get all the paperwork you demand, minimizing the chances of you getting cheated.