Fineness, solders, filling and coatings
Fineness and solders
The fineness of an article of precious metals refers to the amount of precious metals in the article; the gold content of gold jewellery, for example. Precious metals are often alloyed with other metals. However, articles of precious metals must meet the minimum requirements for precious metal content:
- gold 375
- silver 800
- platinum 850 and
- palladium 500 parts per thousand for each precious metal by mass.
Permitted precious metal alloy finenesses and solders PRECIOUS METAL CHEMICAL SYMBOL FINENESS* LOWEST ALLOWED FINENESS OF SOLDER Gold Au 999 750 Gold Au 916 750 Gold Au 750 750 Gold Au 585 585 Gold Au 375 375 Silver Ag 999 550 Silver Ag 925 550 Silver Ag 830 550 Silver Ag 800 550 Platinum Pt 999 Solder’s fineness of precious metal is 800
Platinum Pt 950 Platinum Pt 900 Platinum Pt 850 Palladium Pd 999 Solder’s fineness of precious metal is 700
Palladium Pd 950 Palladium Pd 850 Palladium Pd 500 *Fineness of articles of precious metals is expressed in thousandth of mass.
If you sell articles of precious metals in Finland, the articles must carry a fineness mark accepted in Finland. The articles must not carry other fineness marks. The precious metal content of an article must be at least the fineness indicated in the mark; lower finenesses are not allowed.
Solders of the article must also 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 necessary for soldering. Any precious metal (gold, silver, platinum, palladium) can be used to solder Platinum and palladium. Only gold should be used to solder gold articles and only silver should be used to solder silver articles.
Please note that there are restrictions on the cadmium content of solders and cadmium should not account for more than 0.01 per cent of the weight of the solder.
Using a sealing material
Other materials for attachment, such as glues and sealing materials, can be applied on articles of precious metals. They can be used to the extent that attaching requires. A sealing material can be used on articles of precious metals to attach stones if the amount of sealing material and precious metals 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
- make jewellery made largely of sealing material
An exception to the rule applies to cutlery, candlesticks and similar items. You are required to provide the customer with a product description on these articles.
Filling
Reinforcing, filling or increasing the weight of an article of precious metals is not allowed with a precious metal, metal or other material or solder with a fineness grade lower than that of the article.
Cutlery, candlesticks and similar articles can be filled in some cases. See When is a product description required for an article.
Coatings
You are allowed to coat articles of precious metals. Remember that the fineness mark of an article with a coating indicates the fineness of the coated precious metal. In other words, the array of marks does not contain one indicating the fineness of the coating material. For example, if an article is gold-plated silver product, it must be stamped with a mark that identifies it as being made of silver. A gold article with a silver-plating must be marked as gold.
For the consumer, platings may present something of a problem. Coatings wear off, and the colour of the article may change over time. If you sell rhodium-plated products to consumers, the buyer should be told about their maintenance when making the sale. The consumer should be made aware before completing the sale that the article should be re-coated every few years, depending on the use, in order to preserve the its appearance. Some articles have been coated using intermediary coatings of copper, for example. Such articles may develop red patches in places where the surface coating wears off.