Precious metals are metals sought after by man for their beauty and their exceptional qualities:


  • Attractive colour and brilliance which last for generations, and are practically eternal.
  • Extraordinary physical properties: they are malleable, conduct electricity, are resistant and hypoallergenic…
  • Cannot be attacked by acids, do not burn when heated, but melt.

Few metals possess such qualities and are rare. They are platinum, gold and silver. In some countries, titanium and palladium also qualify as “precious”.

  • Pure gold is too « soft » to be used in jewelry. It is therefore mixed with other metals (copper, silver, palladium, etc.) to form a robust alloy capable of withstanding shocks and retaining stones.
  • Its purity is measured as follows:In jewelry, 750 ‰ gold, 925 silver or 950‰, and 950‰ platinum is used.
    • in carats (from 1 to 24 on a scale of 24), for example 18 carats = 18/24 pure gold in the alloy, 14 carats = 14/24 pure gold or
    • in 1000ths : 750‰ = 18 carats, 585‰ = 14 carats

Since 18 carat gold is an alloy, by changing the structure of the alloy, you change the colour of the gold to obtain shades ranging from grey, to yellow green, pink and red.

Since platinum is used almost pure (950‰), its colour cannot be changed.

Jewelry in black, brown or blue gold is treated on the surface. This coating may wear with time, but can generally be renewed.