If it is copper, it will be either a Penny, a Halfpenny or a Farthing. All three coins are virtually identical except for size.
The Penny is 35mm in diameter.
The Halfpenny is 29mm in diameter.
The Farthing is 21mm in diameter.
Whatever it is, if it is uncirculated and in absolute mint condition, it could fetch anything from £150 to £300 GBP.
If it has been circulated but still in good condition, it might fetch up to £10 to £70 GBP.
A reputable coin dealer will be able to give a more accurate valuation and help with a positive identification.
Please check your coin. Queen Anne was on the throne on in 1709, George I did not come to the throne until 1714.
You need to give us a bit more information, particularly what is the main motif on the coin (Britannia, a shield, etc.) and an estimate of what the coin is made out of (gold, silver, copper, etc.) and then we can better identify what it is and hopefully get you a value.
You have a British coin ("Georgius IV D.G. Britannia Rex F.D." is abbreviated latin for "George the Fourth, King of Britain and Defender of the Faith") dated 1821. To get a value, the denomination and condition of the coin would need to be known.
what is the value of the revolution bicentinniel coin of George Washington gold coin
The same as every other 2-headed or 2-tailed "magician's coin" - a couple of bucks as a novelty item but no collector value because it's a privately-made trick coin.
The value of a George VI half crown coin will depend upon its condition and how much the seller wants for it. You can expect to pay anything in the region of $1-$30 for this coin at auction.
Please check your coin, George III died in 1820.
€427
The only George III coins with Britannia on the reverse are the Twopence, Penny, Halfpenny and the Farthing, but none of them had a milled edge. From 1797, the Penny was 36mm in diameter, the Twopence was 41mm in diameter and both coins were made from copper.
Britannia can be found on the reverse of a Britishnon-commemorative 50 pence piece. Britannia also appeared on predecimal Pennies and pre-1936 Halfpennies.
The U.S. did not start minting quarters until the 1790s. In fact, the U.S. did not even exist in the 1500s! Please check your coin again and post a more detailed question, including a description of the design and wording on the coin.
What type of coin? It sounds more like a medallion??