.. Is there, or has there ever been a 20 Karat White Gold alloy?
I do a lot of restoration on antique jewelry, and I've seen a couple
watches in 20K white gold. I remember seeing this high karatage
white gold used to make watches, and maybe once or twice for a ring.
Perhaps it's because they would have used a very high percentage of
nickel to get a white color, which would make for a pretty stiff
material. I believe those watch cases were largely die struck. They
were also thin material. I don't know why they couldn't have gotten
just as much rigidity with an 18K alloy. There may be some other
reason that someone knows as to why they would choose 20K. I'll ask
one of my antique jewelry dealers I repair for if they know.
David L. Huffman