The Guinea is a famous British gold coin minted between 1663 and 1814. The coin was originally created as a one pound coin (20 shillings) but is better known as being worth One Pound and One Shilling (21 shillings).
After the English Civil War, King Charles II introduced new coinage. A gold coin, approximately a quarter of an ounce, was issued and for the first time it was not hammered. Made by machine using gold from the Guinea Coast of West Africa the coin probably became the most important coin of the realm.
Originally 20 shillings, the coin actually fluctuated with the gold price, at times being as high as 30 shillings. In 1717 the Guinea became fixed at 21 shillings (in today’s money that is £1.05). Other coins of the family were also minted, such as half-guinea, two-guinea and five-guinea.
In the Great Recoinage of 1816 the Guinea was replaced by the Pound and the Sovereign became the gold coin in use. Long after the Guinea was retired the name continued to be used, especially for prestige purchases intended for the more wealthy. Even now racehorses are still sold in Guineas (the auctioneer traditionally taking the 5p as commission).
Guineas are 25mm in diameter, weigh about 8.38g and are 22 carat gold (91.6%). Prior to 1717 they weighed slightly less (around 8.3g) and were made of 91.34% gold.
On eBay UK:
 | 2017 Full Gold Sovereign Coin £ 853.30 |
 | 22ct gold sovereign1912 coin with 18ct gold mount £ 618.70 |
 | 1982 Queen Elizabeth II Gold Sovereign Coin Ring – St George & Dragon – 10g £ 863.61 |
 | 1892 Victoria Gold Half Sovereign | Jubilee Head | Shield Back | London Mint £ 465.00 |
 | 1974 Elizabeth II Full Gold Sovereign Coin £ 843.10 |
 | 2005 gold bullion half sovereign in original rm packaging unopened £ 516.70 |
 | 2022 1/4 Gold Sovereign Coin Queen Elizabeth II Obverse Royal Arms Reverse £ 470.80 |
 | 1817 George III Gold Half Sovereign very Fine £ 822.70 |
On eBay USA:
| 2017 Full Gold Sovereign Coin £ 853.30 |
| 22ct gold sovereign1912 coin with 18ct gold mount £ 618.70 |
| 1892 Victoria Gold Half Sovereign | Jubilee Head | Shield Back | London Mint £ 465.00 |
| 1974 Elizabeth II Full Gold Sovereign Coin £ 843.10 |
 | 1/8 Sovereign Gold Coin — Hattons of London — Boxed £ 135.90 |
 | 2026 Quarter Solid Gold Sovereign Coin - 22ct. In Royal Mint Sealed Pack. £ 310.00 |
| 2022 1/4 Gold Sovereign Coin Queen Elizabeth II Obverse Royal Arms Reverse £ 470.80 |
 | Sovereign Bullion Coins of the World 1/500 Oz 999 Gold Coin 3000 Fr. Chad 2020 £ 57.08 |