Wow a gold ring rang that high? Good to know. Congrats.
10K gold in eyes of the Jewelry world is barely considered gold. Sure if it's processed then you have a small amount of pure gold. My point is the alloy mixed with the pure gold is what gives you the higher conductive numbers. 10-karat gold consists of 10 parts gold and 14 parts other metals such as copper, silver, nickel and who knows what else if it was a machine made ring from a large company who most likely out sources their materials(dare I say from China??).
That's why gold rings up all over the VDI scale from foil to zincoln.