If I may add one more thought...I so appreciate your viewpoint. You are right, vintage will be a better choice. I am so excited. I have soooo many Chanel necklaces. I am going to consign some so I can make this a reality. I wore just the necklace today to a doctors appointment and while I was waiting on the doctor, I just kept staring at my necklace. It is so pretty! I love Chalcedony. My wardrobe is 90% black, so the white gold and the chalcedony just pops.
Each chalcedony stone is a work of nature. Each stone is beautiful in itself.
As you buy your pieces, it may be difficult to get an exact match of the underlying hue. I personally would not stress out about that nor make it the goal. I would look at each piece separately, and if you love the stones in that piece, even if the hue may be a bit lighter or darker, go for it. The goal is to have beautiful pieces that stand on their own.
To me, the look of a bunch chalcedony motifs, each unique works of nature, is beauty in itself.
Just a thought for perspective.