Reply To: Where to buy hydrothermal rough and imitation diamond? › Forums › Cutting Material and Identification › Where to buy hydrothermal rough and imitation diamond? › Reply To: Where to buy hydrothermal rough and imitation diamond? May 28, 2018 at 10:05 am #4706 Justin PrimParticipant @justinprim RUSGEMS has hydrothermal and flame fusion and almost every other synthetic though Im not sure about synthetic diamonds. I buy from them regularly and they are great and the material is great too.