750 gold stamp

A 750 gold stamp will usually refer to gold with a 750 hallmark. The 750 gold stamp shows the metal is 75% gold, with 25% made up of another metal(s).

A 750 gold marking is one of the internationally accepted fineness marks. Fineness is a numerical representation of the gold content of an alloy, in parts per thousand. An alternative measure of purity is 'carat'. Gold carat shows the gold content of an alloy in parts of 24.

Fineness of 999.9 – or 24 carat – is virtually pure gold. A fineness of 750, as indicated by the presence of a 750 gold stamp, is 18 carat. Neither fineness, nor carat, define what other metals are alloyed with the gold. Read more about why jewellers use gold alloys.

750 gold marking

A 750 gold marking will likely be the hallmark, a reliable indication of the precious metal content used in gold jewellery. This is important because, depending on the gold content, two apparently identical gold rings can have significantly different values. A legal 750 gold marking should look like either of the images below.

The UK Hallmarking Act (1973) requires all gold items over 1 gram to be hallmarked. Hallmarking must be administered by recognised assay offices, to ensure that hallmarks are applied independently and by a trustworthy body.

Traditionally, common control marks consisted of four punches. These were; the maker or sponsor mark, the assay office mark, the date mark, and the proportion of precious metal or fineness mark. The 1973 Hallmarking act removed the date from the compulsory marks. This left just assay office, maker, and the fineness as standard marks.

Because of its softness, 750 fineness or 18 carat gold, is less common for jewellery than harder 375 or 9 carat gold. 750 gold is used more in simple designs such as solid wedding rings, as these are less likely to be damaged than intricate designs.

Colours of 750 gold

Depending on the alloy, 750 gold appears in three basic shades: yellow gold, white gold and rose. 750 pink gold is a lighter variation on rose gold, and is seen only occasionally. A huge range of other coloured golds are also possible; these include green, grey, purple, blue and black.

Yellow gold is the most popular, and the shade most commonly thought of as 'gold'. It is an alloy of gold, silver, copper, and possibly zinc. Because yellow gold is mixed with silver, another noble metal, it is highly hypo-allergenic – that is unlikely to cause an allergic reaction. This also makes it more tarnish resistant.

White gold appears almost like silver or platinum. A very popular gold for jewellery, it is an alloy of gold and silver, platinum or palladium. Parts of nickel and zinc may also be added. The hardness of platinum or palladium makes white gold extremely durable and scratch-resistant. Plus, white gold jewellery is usually rhodium-plated to give a pure white appearance.

Rose gold gets its reddish tint from the inclusion of copper, though small amounts of silver may also be part of the alloy. The relatively low cost of both copper and silver make it a more affordable option.

Purity applications

Investment gold is defined by HM Revenue and Customs as having a purity of not less than 900 thousandths. This is between 21-22 carat and above. For this reason, bullion gold bars are 24 carat, and coins either 22 or 24 carat. Serious gold investors therefore would not consider buying under 22 carat gold.

The weight of gold investment coins is generally measured by their gold content, excluding any other metals. For example, 'one ounce' gold coins, struck from less than 24 carat gold, contain one ounce of pure gold plus the other metals. As result, and slightly confusingly, some gold investment coins will actually weigh more than their stated weight!

The gold Krugerrand coin is a good example of this. The Krugerrand is made of 22 carat gold, with copper being used to improve the strength of the coin and produce the distinctive red tint the coin is known for. Despite being 22-carat gold it is still worth the same as a one ounce 24 carat gold, because the amount of gold content in both is the same - 31.103 grams.

Jewellery buyers, unlike gold investors, will balance appearance and value against practicality. 24 carat would be too soft and impractical for general wear. 750 fineness gold is more practical, though not as hard-wearing as 375, which may tarnish. 375 is, therefore, not regarded as fine jewellery. At BullionByPost we buy 750 stamped gold at market-leading rates. More information regarding the sale of 750 gold can be found on our 18 carat scrap gold page.