They're not all that rare. If dirty and corroded, about 5 cents each. Really nice uncirculated examples can be bought from a dealer for $1 or $2.
Pennies in the United States are made primarily of zinc with a thin copper coating. The composition changed in 1982 when pennies transitioned from being made of mostly copper to mostly zinc due to rising copper prices.
Yes zinc is used in pennies and it is used in sunscreen.
If you mean a coin blank that has not been struck, but still has its copper coating, that's called a "flan" and is only worth about $1. If you mean a coin that has been struck with the Lincoln images but does not have its copper coating, you'll need to have it examined in person. If the missing copper is due to being dipped in acid, the coin is essentially worthless. But if it came from the Mint that way it's a fairly rare error that could be worth up to $100 retail.
No, pennies do not contain gold. Modern pennies are mostly zinc with a little copper, older pennies are mostly copper with a little zinc.
A penny worth one million dollars is typically a rare coin, such as the 1943 copper penny. Most pennies from that year were made of zinc-coated steel due to wartime metal shortages, but a few copper pennies were mistakenly minted. Collectors value these rare coins highly, with prices reaching up to a million dollars or more at auctions or private sales.
Although US one-cent coins (pennies) were once mostly copper, today they are 97.5% zinc with a copper plating. Copper nails are rare due to the metal's malleable nature, but zinc nails can be plated with copper as are pennies. Brass is an alloy of copper and zinc, and is widely used.
Pennies today are made of 97.5% zinc and 2.5% copper.
100 pennies = 100 [pennies].
Newer pennies are primarily made of zinc, with a thin copper plating on the surface. The core of these pennies is composed of 97.5% zinc and 2.5% copper.
The pre-1982 pennies are 95% copper and 5% zinc. Post-1982 cents are 97.5% zinc and 2.5% copper.
Zinc is the base of US pennies made after 1982.
Since 1982, pennies have been 97.5% zinc and 2.5% copper. Before that, they were 95% copper and 5% zinc.