Testing and marking is the main activity of the Assay Office
The control an testing consists in checking and verifying the fineness and prescribed state of the precious metals articles. The legal fineness and prescribed state are stipulated by the Hallmarking Act. The result of the control and testing is the official marking of the goods with a hallmark corresponding to the legal fineness standard, or with other means stipulated by the Hallmarking Act.
The following items are subject to mandatory hallmarking:
- domestic and imported goods intended for domestic trade, presented for hallmarking by a manufacturer or importer enrolled in the register of producers and traders kept by the Assay Office,
- old goods (goods which have not undergone hallmarking in the past and are to be traded),
- repaired goods (goods originally officially marked, where the part marked with a hallmark has been removed during the repair),
- medals and plaques minted before 1939, if they are not firmly affixed to the article(e.g. soldering or riveting),
- medals and plaques minted before the end of 1992 by the State Mint in Kremnica and marked with a coin mark consisting of a capital letter "K" in a horizontally hatched octagon.
The following are not subject to mandatory hallmarking:
- goods completely enamelled and goods in which the weight of the precious metal is of minor importance in relation to the weight of the other materials used (eg. closures, frames and handles of stones, lugs, etc.),
- very light goods, (e.g. goods with weight which does not exceed 0.5 g for gold and platinum articles, and 2.0 g for silver articles) - so called weight exemptions,
- imported goods placed under a customs procedure of a suspensive arrangement or under a procedure with economic impact,
- Slovak and foreign coins,
- domestic goods intended for export.
Testing of other articles and items made of precious metals.
In accordance with the Hallmarking Act, the Assay Office supervises the minting of Slovak coins by verifying the fineness of each minting. The Office further verifies the fineness of dental precious metals and gold and silver foil. In addition to former, the Assay Office, at the request of the applicant (citizen or entrepreneur), ascertains the content of precious metals in the submitted items, jewellery alloys, scrap and samples, which are not subject to mandatory hallmarking. If it is advisable, and if the owner agrees to it, the Assay Office shall melt or otherwise modify the submitted items. The Office will issue an official attest of the result.
The Assay Office will not carry out the testing and verification of the content of precious metals, unless it is within its technical capabilities, or the submitted items are medically or hygienically harmful.
Testing of a fineness of precious metals.
Jewellery alloys used for the production of precious metals articles must have the prescribed legal fineness and, in addition to main precious metal, may contain only metals, the use of which, is permitted by the executive directive.
Jewellery alloys, which are of legal fineness and comply with the provisions of the Hallmarking Act, are entered in the list of registered alloys at the request of manufacturers or traders, after prior examination by the Assay Office.
Fineness tests are performed by:
- non-destructive testing on a touchstone,
- XRF analysis
- chemical analysis,
- testing of gold (cupellation method STN EN ISO 11426),
- testing of silver (potentiometric titration STN EN ISO 11427),
- testing of platinum (gravimetric method STN EN ISO 11210).
Marking of precious metals articles.
Goods that have the legal fineness, prescribed condition, comply with other legal requirements and are marked with the responsibility mark, shall be marked with the corresponding hallmark or otherwise by the Assay Office.
Marking is performed by:
- mechanical imprint of the stamp,
- laser marking,
- hanging of a seal with the corresponding hallmark,
- issuing of a certificate.