Most pearls in Mainland China are of the freshwater/brackish variety and are pretty, plentiful and very inexpensive. Depending on where you are and who you meet, knowledge of high-end cultured sea pearls and other rare pearls may be rare. I'm sure the pearls you have are very nice and classy but it may not be perceived the same way a strand of nice pearls are here in the west, Japan or Hong Kong. For example, the Jackie O simple sheath + pearls is seen as dressing down in the Mainland rather than dressing up as it is here. Um, I'm not sure if I'm explaining this properly....
I just reread the part where you mentioned that you're the grandmother?
In that case, go formal as it would be expected of you as part of the wedding party and as the grand matriarch. You would most likely be given a pinned corsage (for some reason they only do pinned corsages in Asia for both male and females) to show that you are directly related to the couple. Pearls are OK as no one would dare say a thing!
When buying red envelopes in Shanghai, make sure you ask for wedding red envelopes and to state that you're the grandmother so that you're given suitably formal envelopes. You'll need a certain number of matching envelopes to divide your cash into for the wedding tea ceremony/ies. The number varies slightly by customs of the families involved so please ask prior to shopping. Your short handwritten message should be on the back of each envelope. The notes should be new so calling ahead to reserve new notes at a bank would be a good idea.
Good luck, have fun and congratulations!
Thanks for all these details
Will wear another necklace
I would never have known about writing on back of envelope
I was planning to write a check (10 thousand - he's our dear first grandchild!!) not give cash
Is this a mistake? Would I be better to give cash in envelopes (yuan not dollars?) and give check separately to bride and groom later?