The merchant won't tell you unless he buys it himself. Some time ago, in order to please his mother-in-law, I specially invited an expert from China Geo University to accompany me to visit Changle Gem City. I watched it for three days and learned a lot. What I am most satisfied with is the dichroism of Changle gem. I took a flashlight from the front: dark blue, side: pan-green. This dichroism is that only characteristic of gem in the world. However, since 2009, Changle Gem has passed the international certification and soared. If there is no ribbon and no growth line, the main body is transparent, ranging from several hundred yuan to several hundred thousand yuan per carat (equivalent to 5 carats per gram). I spent hundreds of thousands on that piece, and it was worth it. At present, a pendant with a dozen carats is at least tens of thousands, and hundreds of thousands are very common.