Solders and other sealing materials
Solders used in articles of precious metals must match the fineness of the rest of the article. Solders with a lower fineness may be used for technical reasons in some cases, but they should only be used to the extent they are needed for soldering.
Gold: gold with the same fineness as the rest of the article is used as the solder. Exception: solders of minimum Au750 for gold products of over Au750.
Silver: silver with minimum fineness of Ag550 is used as the solder.
For soldering platinum, any precious metal may be used (Ag, Au, Pd, Pt), provided that the precious metal fineness is at least
- in a platinum article: 500
- in a palladium article: 700.
Note that the cadmium content of solders is restricted (link to cadmium restrictions) and may not exceed 0.01% of the weight of the solder.
Sealing materials and glues
Instead of soldering, such products as glues and sealing materials may be used for articles of precious metals. They can be used to the extent needed for attachment purposes. A sealing material may be used to attach stones on articles of precious metals if the amounts of both the sealing material and precious metal are clearly visible.
You are not allowed to
- fill an article of precious metal with a sealing material
- use a sealing material to add weight to or reinforce jewellery
- produce a piece of jewellery largely made of sealing material.
An exception to the rule applies to cutlery, candlesticks and similar items, read more.
