I have wondered about this too John.
Looks like opinions vary some about this.
With so many different sizes and styles of gold rings, they can show up all over the place, so I do not worry about it much.
I found two rings at the beach last month... one 10k and one 14k and both yellow gold, but different sizes and styles.
The 14k read 8 on my 800 and the other one read 15k.
They were different sizes and styles.
A couple years ago, I found 423 nickels in one year and not one piece of gold although I know gold can give the same reading.
Felix, that is quite surprising to pull that many nickels with no gold. Strange thing today in that I went out for about an hour and a half (first time out in about 6 months). Found $3.01 in clad and what I THOUGHT was a small silver ring. It rang up at 49 VDI (quarter range) and came out shiny with no rust. Buried about 2 inches deep. However, when I got it home and cleaned it up, there were no markings and it appears to be plated, with some of the plating coming off, but with shiny silver underneath as well. What of that color would ring up like silver but with a small size? Oh well, another one to ponder.