There are brass ones and nylon ones.
Compression rings are made of cast iron.
Normal piston have 2 compression rings and a 3 piece oil ring. Some aftermarket rings have a 2 piece zero-zap second compression ring to reduce blow-by.
loss of power
2 compression rings and one oil control ( helps scrap excess oil off cylinder walls)
If you're getting gasoline in the oil, then you have bad piston rings that are allowing gases into the crankcase. You can find which piston(s) have bad rings by doing a compression test; a cylinder with bad rings will have lower compression.
Compression blowby is air, fuel, and exhaust gasses slipping past the piston rings into the crankcase.
You don't repair compression rings you replace them.
It is the leakage of compression gasses past the piston rings.
Bad compression rings can allow gasoline to get into the oil.
Bad compression is usually worn out piston rings, no compression is usually bad valves - assuming it's a 4-stroke.
Gently squeeze them back and forth until they break and use new ones. They make plastic compression rings that don't dig in, but I don't like them as they can slip or split.
compression rings on pistons are worn out or broken