Certification & Authenticity

All “byMZ” jewellery is officially certified by the Portuguese Contrastaria (Assay Office), an official service integrated into INCM – Imprensa Nacional Casa da Moeda (Portuguese Mint).

The hallmark applied by the Contrastaria guarantees the precious metal content of each piece, confirming that it meets the legal standards required to be placed on the market. The hallmark appears alongside the maker’s or sponsor’s mark.

For silver, hallmarking is only required on items weighing over 2 grams, and for gold on items above 0.5 grams.

If you would ever like extra reassurance, you can always request a verification of authenticity directly from the Assay Office, “byMZ” registered activity numbers are 1000034364 and T10829.

You can view the official Portuguese hallmarks here: https://contrastaria.pt/marcas-da-contrastaria-portuguesa/

For daily silver and gold prices, please visit:
LBMA Precious Metal Prices
APIO – Portuguese Jewellery Industry Association.