Buying pearls online is not reliable. I think it is more reliable to buy pearls at Tmall, because Tmall is the flagship store of the brand, and the authenticity is guaranteed. Besides, everything you buy is returned for seven days without reason. If you don't like it, you can return it if you think it's not genuine. Things bought online should be cheaper than those bought in physical stores. After all, online competition is greater, there is comparison, and it is difficult to sell if it is expensive.
I bought the products of Olivia, Nanzhu Palace Jewelry Flagship Store and Jingrun Jewelry Flagship Store in Taobao Tmall Store, and I feel ok and quite reliable.