The country of origin and the denomination of the coin would be a big help. Holes in the centre of coins is no longer as widespread a practice as it once was, although some countries continue to do so as a tradition.
Originally coins were different sizes because their values were determined by how much metal they contained. For example, a US dime had roughly 10 cents worth of silver in it, a British sovereign had roughly a pound's worth of gold, etc. People could associate a coin's value with its size, making it easy to tell them apart. Even though circulating coins today don't have any precious metals in them, different sizes still help people to easily distinguish one coin from another without looking at its design or denomination. Having different sizes also facilitates the use of mechanical sorting equipment. Mixed coins are passed through a kind of filter with holes of increasing sizes. The smallest coins drop through the smallest holes first, the next size coins drop through the second set of holes, and so on, and are collected in bins.
You can put coins in an mouldy wrapping and some of the mould spores will rub off onto the coins. This will make the coins LOOK mouldy but, being metallic, they will not actually be mouldy.
No, coins are not an element. Some coins may be made of nearly pure gold, silver, aluminum, or other metal elements, but most present-day coins are made of various metal alloys, often with different composition on the inside than on the outside.
Reeding is the type of textured or grooved edges on some coins. U.S. dimes and quarters are reeded, but cents and nickels are not. The reason some coins have reeding is because when coins were made of precious metals like gold and silver, sometimes people would shave off a little of the coin to keep for themselves, to collect and sell at another time. By adding reeds, coins couldn't be altered without noticeable marks.
The mint does not drill holes into the coins. If a hole is drilled into a coin it dramatically reduces value. MANY COUNTRIES DRILLED HOLES IN THEIR COINS. THE COINS WERE WORN FOR JEWELRY AND THAT RENDERS THE COIN PRETTY MUCH WORTHLESS.
You do not provide any detail. If it is a general circulation coin, it is worth nothing. Modified coins are worthless. There were no British coins minted with holes in the centre. On the other hand, you may have a medallion of some sort.
They don't have holes in them. People do that to wear them as jewelry, and it completely destroys the value.
Japan (the 5 yen coin) Papua New Guinea (One Kina)
1234 coins
They never have. If your coin has a hole and is a US coin then someone drilled it in. It was not done at a US mint.
Some things that have holes in them are donuts, cheese graters, strainers, and colanders.
The Japanese yen is the official currency of Japan. Some of the coins have holes in the middle and the paper currency looks similar to American currency with pictures of Japanese political figures on it.
Normally, A Standard Course Would Have 18 Holes. Some Have 9, And Some Even Have 27 Holes.
There are usually 18 holes in a golf course; some have 9 holes or some multiplier of 9 holes. I have played at golf clubs with 9, 18, 27 and 36 holes. However, a standard "round of golf" at most golf clubs / courses involves 18 holes.
Well sometimes you can dig holes around a rock and the bang it over and over and you will get coins
The country of origin and the denomination of the coin would be a big help. Holes in the centre of coins is no longer as widespread a practice as it once was, although some countries continue to do so as a tradition.