Gold Grade

Gold Grades, Fineness and Karat / Carat
Gold is graded in karat / carat. A karat (carat) is a measurement of the fineness of gold. The gold grade expresses the proportion of gold in a gold alloy or the quality of that gold alloy. Pure gold or fine gold is 24 karat / 24 carat (24k, 24 kt, 24 ct) gold (.999). 24k gold (999 fineness) is the grade of gold bullion.

Gold Karatages (Caratages)
The grades of gold reduce in karat fineness as more non-gold metal (alloy) is mixed with gold. Pure fine gold is very soft and malleable and does not lend itself well to gold objects that receive a lot of wear, as pure gold wears easily. The next grade down from pure gold is 22 karat (22k) gold (.916) , which is somewhat harder but is still easily worn away, especially if in contact with gold of lower grades. 22k gold is used in some gold coins and investment jewellery (jewelry).

18 karat (18K) gold (.75) is used for high quality jewellery (jewelry) and is the most commonly used grade in Continental European jewellery. It is considerably harder than the two previous grades but still wears more easily than 14k grade gold and lower grades of gold. It is advised that two different grades should not be worn together in order to limit the wear that could occur.

14 karat (14k) gold (.583) is the most common grade of gold used in North America. This is considerably harder than the most common UK gold grade, which is 9 karat (9k) gold (.375). There are other grades of gold, notably 15 karat (15k) gold (.625); 12 karat (12K) gold (.5) and 10 karat (10K) gold (.417). The lowest grade of gold that is acceptable for jewellery is 8 karat (8k) gold (.333)

All jewelry in the USA and jewellery in the UK. is required by law to be stamped so consumers will know the quality of gold used. This has not always been the same, even since the time of compulsory hallmarking in the UK - the reason being that some items are just too small for a hallmark to be useful in identifying the gold purity.

North America usually marks jewelry with the karat grade (10K, 14K, etc.), Other countries have different gold hallmarking conventions, for example jewellery made in the UK or Italy has a fineness stamp (417, 583, etc.).