"Circa 1892" suggests an approximate date. Either it is, or it is not an 1892 coin.
The Jubilee bust (crowned) of Queen Victoria appears on the obverse of all British gold and silver coins for the period late 1887 to early 1893.
The only one of the Sovereign coinage of this period to have a shield on the reverse is the Half-Sovereign coin with a diameter of 19.3mm.
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A British 1892 gold Half-Sovereign (Victoria)(Crowned Shield)(lower shield, date spread apart), circulated but still in good condition, might fetch anything from £70 to £275 GBP.
A British 1892 gold Half-Sovereign (Victoria)(Crowned Shield)(high shield), circulated but still in good condition, might fetch anything from £70 to £275 GBP.
A British 1892 gold Half-Sovereign (Victoria)(Crowned Shield)(Jubilee bust, lower shield, date spread apart), uncirculated and in absolute mint condition could fetch up to £125 GBP. If it has been circulated but still in good condition, it might fetch anything from bullion value up to £85 GBP.
The values quoted are the best possible for the best specimens in their grades, but may be significantly lower due to varying demand for the coin and the prevailing economic climate. A reputable coin dealer will be able to give a more accurate valuation based on inspection of the coin.
A British 1862 Sovereign (crowned shield)(Roman I), circulated but still in good condition, might fetch anything from £250 to £600 GBP. A British 1862 Sovereign (crowned shield)(wide date), uncirculated and in absolute mint condition could fetch up to £400 GBP. If it has been circulated but still in good condition, it might fetch anything from bullion value to £220 GBP. A British 1862 Sovereign (crowned shield)(inverted "R" in VICTORIA), is considered extremely rare. A British 1862 Sovereign (crowned shield)(inverted "A" in DEF, narrow date), is considered extremely rare. A reputable coin dealer will be able to give a more accurate valuation.
The 1883 Half-Sovereign has a crowned shield on the reverse. The mintmark, if one exists, will be below the shield. Royal Mint London - no mintmark Melbourne Mint - "M" below the shield Sydney Mint - "S" below the shield
Such a coin does not exist. The Sovereign was not reintroduced into the British currency until 1816. You may have a One Guinea of Half-Guinea coin. Either way, there are no known examples of either of these coins in mint or uncirculated condition. The Guinea coin has an unflattering image of George III on the obverse and a crowned, spade shaped shield on the reverse. Both coins have an unflattering image of George III on the obverse and a crowned, spade shaped shield on the reverse. The Guinea coin is 24mm in diameter, a little larger than a Sovereign. The Half-Guinea coin is 20mm in diameter, smaller than a Sovereign, but slightly larger than a Half-Sovereign.
Please check your coin. The 1837 gold Half-Sovereign coin had the "Crowned Shield" design on the reverse with William IV on the obverse. The St. George design first appeared on the Half-Sovereign coin in 1893.
The obverse of any King George coin will have King George on it. From 1714 to 1952 there were 6 King Georges. From 1714 to 1800, the reverse of the British silver Penny had a Crowned "1" on it. From 1797 to 1967, the reverse of the British copper and bronze Penny featured the seated figure of Britannia holding a trident and shield.
There are two possibilities- A Sovereign which is 22.05 mm in diameter. St.George and dragon on reverse. A Half-Sovereign which is 19.3 mm in diameter. Crowned shield on reverse. See the links to related questions.
British Farthings from 1953 to 1956 featured Queen Elizabeth II on the obverse and a wren on the reverse. British Farthings from 1937 to 1952 featured King George VI on the obverse and a wren on the reverse. British Farthings from 1911 to 1936 featured King George V on the obverse and a seated Britannia with trident and shield on the reverse. British Farthings from 1902 to 1910 featured King Edward VII on the obverse and a seated Britannia with trident and shield on the reverse. British Farthings from 1838 to 1901 featured Queen Victoria on the obverse and a seated Britannia with trident and shield on the reverse. British Farthings from 1831 to 1837 featured King William IV on the obverse and a seated Britannia with trident and shield on the reverse. British Farthings from 1821 to 1830 featured King George IV on the obverse and a seated Britannia with trident and shield on the reverse.
A British 1885 22 carat gold Half-Sovereign (Victoria)(crowned shield), uncirculated and in absolute mint condition could fetch up to £375 GBP. If it has been circulated but still in good condition, it might fetch anything from bullion value to £225 GBP. A British 1885/3 22 carat gold Half-Sovereign (Victoria)(crowned shield), uncirculated and in absolute mint condition could fetch up to £750 GBP. If it has been circulated but still in good condition, it might fetch anything from £90 to £375 GBP. A British 1885 22 carat gold Half-Sovereign (Victoria)(crowned shield)(minted in Melbourne - mintmark = M), uncirculated and in absolute mint condition could fetch up to £6,750 GBP. If it has been circulated but still in good condition, it might fetch anything from £140 to £2,000 GBP. NOTE - The reverse of these coins is upside down to the obverse. This is normal. The values quoted are the best possible for the best specimens in their grades, but may be significantly lower due to varying demand for the coin and the prevailing economic climate. A reputable coin dealer will be able to give a more accurate valuation based on inspection of the coin.
King George II ruled Britain from 1727 to 1760. His image appeared on the following British coins - Gold - Five Guineas, Two Guineas, One Guinea, Half-Guinea Silver - Crown, Halfcrown, Shilling, Sixpence, Fourpence, Threepence, Twopence, Penny Copper - Halfpenny, Farthing
A British 1861 22 carat gold Half-Sovereign (Victoria), uncirculated and in absolute mint condition could fetch up to £595 GBP. If it has been circulated but still in good condition, it might fetch anything from £65 to £250 GBP. NOTE - The reverse of these coins is upside down to the obverse. This is normal. The values quoted are the best possible for the best specimens in their grades, but may be significantly lower due to varying demand for the coin and the prevailing economic climate. A reputable coin dealer will be able to give a more accurate valuation based on inspection of the coin.
Your coin could be a gold Guinea (with a crowned shield) or Half-Guinea (with a crowned "spade" shaped shield) or a copper Halfpenny or Farthing (with a seated Britannia), the only four British George III coins minted by the Royal Mint in 1773. Most coins minted during this period had the reverse upside down to the obverse and had no denomination on them. Can you provide more information?
The English do not produce a coin known as a "quarter". Perhaps you refer to a British "Shilling" being approximately the same diameter as a US "Quarter". The 1958 British Shilling comes in two varieties. Both feature Queen Elizabeth II on the obverse, the difference is on the reverse. The "English" reverse shows a crowned shield with three lions. The "Scottish" reverse shows a crowned shield with a rampant lion. Both coins have FID DEF and ONE SHILLING inscribed on the reverse. See the related question at the link below.