Marking & Hallmarking Preciuos Metals
As a minimum, all items of jewellery is stamped with a ‘fineness mark’ declaring the content of precious metal in the alloy.
A hallmark is a mark or series of marks struck on items made of precious metals – platinum, gold, silver and palladium. Hallmarks guarantee a certain purity or fineness of the metal.
National hallmarking systems differ from country to country. In South Africa, the following are the most popular caratages which are stamped on jewellery:
|Pt950; Pt900; Pt850||9ct or 375; 18ct or 750||SIL, S925 or 925; S835 or 835|
Combination Metal Jewellery
The jeweller can often use more than one type of metal in a piece of jewellery in order to create a different look and feel.
Your jeweller can advise you regarding this and disclose the different metal content. These can be distinguished in two groupings:
Products where both metals are visible
Combinations between white gold and yellow gold have become very popular. White gold is often used for the metal that holds a diamond (the setting) to enhance the visual impact. In this case, the hallmark will only indicate the purity of the gold.
When silver is combined with gold, the two sections are often stamped separately, indicating which section is silver and which gold, also containing the purity of each metal in the hallmark.
Products where only one metal is visible
In some cases, gold will be manufactured in a hollow form, often used in earrings to minimise the weight. To strengthen the gold and prevent damage, the product is then filled with silver.
These products will carry a silver hallmark or have a combination hallmark that shows the % gold content and the % silver content
Plated jewellery and bonded gold jewellery
Plated refers to a piece of jewellery that is made from a metal such as copper or silver and then covered, through an electroplating process, with a thin layer of precious metal, usually gold. The product is usually hallmarked only based on the silver content and not a gold hallmark.
This form of jewellery, classified as costume jewellery, is more affordable than fine gold jewellery. The plating will wear off in time but can be replated to restore the original look.
‘Bonded’ refers to jewellery where gold is bonded through heat with the original metal, often silver. The bonded product contains a much thicker layer of gold that is less likely to wear through. You will either find a silver hallmark or a combination hallmark specifying the silver and gold content separately. Your jeweller has a responsibility to advise you as to the product you are purchasing.