Some of the most valuable British coins are early large-sized guineas, large British gold coins, the British Proof Sets and early sovereigns before Queen Victoria. Generally, coins with higher values are uncirculated coins that maintain their pristine state of preservation.
Heavily worn and damaged coins are worth less than coins exhibiting average wear. Coins with high premium values are those with minimal or no scratches, spots and stains. This is what is known as mint condition. Coins from Great Britain sometimes do not bear inscriptions indicating their origin. Coins that indicate British origins are those with inscriptions of Britt, Britannia, Brittaniarum or of British rulers Anne, George, Victoria, William, Edward and Elizabeth, usually with the inscription Dei Gratia, which means "by the grace of God."
Early large-sized guineas are very valuable gold coins owing to their gold content and intrinsic age and beauty, states CoinQuest. An example is the gold coin coming from the period of George III that appears around the size of a U.S. fifty cent coin. This coin is worth about $1,000. Very large gold coins from Great Britain usually contain more than one Troy ounce of the precious metal and derive their value from the gold. Some earlier coins, such as 5-pound gold coins issued during the early 1800s, reach up to $10,000 in value.