✅ SOLVED Some sort of tag.

[WHADIFIND]

This last piece is really kind of strange.
I wish I had a "before" pic because this
thing looked exactly like one of those really old
coppers that have been buried a long time in a wet area.

The green corrosion was REALLY thick! I didn't see any indication
that it was a coin and couldn't see ANY detail. Nothing after soaking
in oil either. So, I hooked it up to electrolysis for a while.

The detail reads "DeZurik FIG# 118S"

The only reference I could find has to do with some sort
of knife valve.

It appears to be copper/bronze/brass and like I said, the
corrosion makes me think it was buried a long, long time.

 

[jewelerguy]

googling DeZURIK comes up that they make valves for waste water and such. I'd say it's a washer or a part of one of their valves

 

[Tony in SC]

I think it's the little tag that is under the nut on a valve or faucet knob/handle. Tony

 

[DCMatt]

From one of these:



1" Dezurik Fig. 118 Threaded Plug Valve