Precious Metals

Silver, gold and platinum are the most popular precious metals and historically were used as currency. Today, these precious metals are most widely used in art and jewellery.

Gold

The physical and optical properties of gold make it ideal for use in jewellery, its beautiful yellow colour; lustre and malleability make it perfect for ornate pieces.

Gold is measured in carats; this is a method of expressing the proportions of the gold present in the piece. In the UK, there are four legal finenesses of gold, 22 carat, 18 carat, 14 carat and 9 carat.

If a piece of jewellery is less than 24 carat, it has been alloyed with another metal, normally rhodium, silver, palladium or platinum.

There are many reasons why gold is alloyed; it could be to change the items properties, for example making it harder, or to change its colour.

Platinum

Platinum has excellent working properties, similar to that of silver and gold, being almost as malleable and ductile. The strength of platinum makes it ideal for setting with diamonds, and other precious gemstones. Platinum is the heaviest of these precious metals weighing almost twice as much as gold. Platinum is a naturally white metal which does not tarnish or wear away.

Platinum is pure so it will always contain 90% or 95% of pure platinum, another reason why it can maintain its rich white colour. Platinum is also alloyed with other metals, in the UK there are four legal finenesses for platinum, these are 850, 900, 950 and 990 parts pure per thousand.

Silver

Silver is a sympathetic metal for craftsman to work with, it has many similar properties to gold. It is a malleable and ductile metal, it bends easily without cracking; its malleability allows it to be drawn in a press so it is suitable for hollowware.

There are four legal finenesses of silver, 800, 925 (Sterling), 958 (Britannia), and 999, most commonly used in UK jewellery is Sterling Silver, these finenesses show the amount of silver to alloy per 1000 parts.

Hallmarking

Hallmarking is a method of guaranteeing the purity of precious metals within the UK Jewellery market. The metals are submitted to an assay office which put the item through a series of stringent tests to ensure the item meets the minimum purity requirements.

It is a legal requirement that all items of solid gold, silver and platinum are hallmarked in the UK, before they can be sold as a precious metal. This law applies to items of gold over 1g, silver over 7.78g and platinum over 0.5g. Items that are plated or made before 1920 are exempt from this law.