C J's Metal Detecting Pages

COINWEIGHTS FOR ENGLISH
GOLD COINS

THE GUINEA

THE GUINEA - in 1662 Charles II ordered that the hand-striking methods of producing coins that had endured for over a thousand years was to cease and that all future coins were to be produced from machine screw-presses. The coins thus made became known as the 'milled coinage'. A new 20 shilling piece was issued in 1663 using gold brought back from Guinea by the Africa Company and for this reason they became known as 'Guineas'. After 1670 the weight was fixed at 129½ grains but the value fluctuated considerably until stabilising at twenty-one shillings in 1717. Half-guineas were also issued as were thirds (by George III only) and quarters briefly by George I in 1718 and George III in 1762. Guineas were last issued in 1813 (and before that 1799) but continued in circulation for some time afterwards. The term 'guinea' was used for pricing goods at 21 shillings for many years after the coin had disappeared and the term only ceased to be used when the shilling became obsolete with the introduction of decimalisation in 1971.
The coin-weights for the Guinea are numerous. Until the reign of George III most have the reigning monarch's head on the obverse and on the reverse a crown over crossed sceptres with 1 GUINEA W. or 1 GUENEA W. below. During William III's reign coin-weights begin to appear with maker's names instead of the king's bust or the bust with maker's initials below. Similarly from 1746 some weights have the initials I.K. or JOHN KIRK below the bust.

By George III's reign some of the guineas had been in circulation for 100 years and many were light in weight. In 1774 a Proclamation declared that from July 15th following, all guineas more deficient in weight than the rates specified were not to pass current except to certain bodies appointed to receive them. This resulted in a four-tier valuation for the guinea at four different weights. This is summarised in the table at the end of this section. All the various weights and values are known on the many examples that exist. These are too numerous to list fully here but the inclusion of any of the weights and figures in the table should be sufficient to identify a guinea weight. Most commonly found from this table are those with the weight and value of type 2 and 3 or the value of type 4. In addition the following phrases are often used:-
1771 OR OLDER
COINED BEFORE 1772
UP TO THE 1ST OF JANY 1772
ACCORDING TO THE ACT OF PARLIAMENT 1775
TO THE NEW STANDARD
NEW GUINEA
Some square coin-weights are used for the first time since 1632. The last official coin-weights for those guineas still in circulation were issued by the Royal Mint during George IV's reign in 1821. They have on the obverse ROYAL MINT 1821 and on the reverse CURT. WEIGHT GUINEA with the weight below. A weight for the one-third guinea of 7 shillings was included in this set.

SUMMARY OF THE 1774 PROCLAMATION

Guineas coined prior to the commencement of the reign
of the King (ie before 1760)

Coin	Value	Weight
One guinea	20s 0d	5dwt 3gr
Half guinea	10s 0d	2dwt 13½gr-13gr
Quarter guinea	5s 0d	1dwt 6¾gr

Guineas coined during the reign of the King and prior
to the 1st of January 1772

One guinea	20s 6d	5dwt 6gr
Half guinea	10s 3d	2dwt 15gr or 14gr
Quarter guinea	5s 1d	1dwt 7gr

Guineas coined since the 31st of December 1771

One guinea	20s 10d	5dwt 8gr
Half guinea	10s 5d	2dwt 16gr
Quarter guinea	5s 2d	1dwt 8gr

New Coins

One guinea	21s 0d	5dwt 9gr
Half guinea	10s 6d	2dwt 16½gr
Third guinea	7s 0d	1dwt 18gr
Quarter guinea	5s 3d	1dwt 8¼gr