Interesting grips. I wouldn't try to polish them. Clean yes...polish no.
Yes it does “work that way”.Lots of interesting comments here. Nice grips. Should be tested for precious metal content. You can't "drop them in a graduated cylinder and get their density" to determine type of metal when there are a variety of metals on the grips. Doesn't work that way. And, again, light and oxygen do not tarnish silver. Sulphur in the air does.
If you plan to sell them, get the metals tested. It may be worth it and have it documented for the buyer! They are quite strikingly beautiful no matter what they are made of!
No laws against that in Mexico and lots of gringos with extra money to spend!
Take 5 90% silver quarters and a clad quarter and throw them in water. Assume they all look the same and you can't tell any difference between them by looks or feel alone. Measure the density, however you would do that, and tell me with certainty which coin is not 90% silver without any other information. It doesn't work that way. The measurement averages over all items measured together, like in the grips. You would have to separate each type of metal and measure separately to tell what each is. I am an analytical chemist.Yes it does “work that way”.
The alloy strikes are claimed to be silver and gold.
If the density is higher than the claimed silver it argues that there is validity to the silver/gold content.
If lower you know it’s largely plate.
The piece has strikes for "Sterling" 92.5 silver which has a density of 10.3 g/cm3.
You are an analytical chemist who is in error.I am an analytical chemist.
Mexico has drug laws too."Actually there are pretty strict laws in Mexico against mis-stamping silver and gold items."