Counterfeit Nickel?

CORRECTION WEIGHT WAS 5.3 TO 5.2

If it is too heavy maybe it was plated. Someone was trying to make a "gold" coin I think and it didn't work. Maybe it was plated with tin or zinc, and these two metals tarnish faster than a regular nickel's metal.

Being a modern coin, it is impossible for it to have been dipped in mercury.

People still can get mercury there in the States? I thought it was banned.

That's kind of different.

I my self just found a similar one from 1984 with a P MM but mine is dull only on the OBV. The REV looks normal, but it scales at 5.5 g. Half a gram OVER Hmmmm...

In the 1950's- to today the big thing was to find a 1943 copper cent. There were also 1944 steel cents. So they would in chemistry take a copper cent and put mercury on it and it would look silver in color and very shiny like a plated cent. But in a few days this would wear off and turn black in color. Unknown to them at that time, the mercury was poisonous and hazardous to the health of the individuals. But they thought it looked neat at the time.

Then they tried to preserve a BU coin with a clear sealer to keep a coin shiny thinking this would preserve it. They were wrong it ruined the coin and did not work.

They tried olive oil on coins to preserve the finish of circulated coins. This looked nice at the time, but olive oil is organic and tended to rot and the coin would smell bad.

Then they tried plating coins to make a 1943 steel cent to look copper. A magnet test would show the coin was really steel and stuck to it.

They the rage was to clean coins with salt and vinegar, copper cleaner, jewelry cleaner and etc. This was done at coin shows. They would go in and buy AU silver coins, take them to their vehicle and dip them and return to sell them to a different vendor as a BU coin.

Then they tried plating coins with gold plating to make it look like the coin was gold. Not they are still selling quarters that are plated with gold or platinum to get people to want these on the TV.

But anything added to a coin, ruins collectable value of a coin. Most time they are trying to make it look like something it is not. So it is best not to try cleaning a coin. But be aware that this does happen when looking a nice coin.

Thanks! Any other possibilities are welcomed.
I like to know what I have.