Ruthenium is a metal that can be found in small amounts within platinum ores. It is rather hard, more so than rhodium, and is considered to be one of the more rare metals on Earth.
Use
Primarily, this metal can be found in alloys of Platinum or Palladium. Why is it there? Small amounts of ruthenium mixed into a platinum alloy will increase the alloy’s hardness, which can sometimes be helpful when working with platinum in jewellery. Though not particularly common in jewellery as a stand-alone material, it is sometimes used as plating for silver jewellery. This allows the silver pieces to remain tarnish-free, and often gives the jewellery a certain darker tone.
Outside of jewellery, it is commonly used as part of platinum alloys in electric contacts as it offers properties similar to rhodium and is less expensive.
Colour
Ruthenium in jewellery generally adds a darker colouring to the jewellery piece. At times, silver jewellery plated with ruthenium might take on the appearance of a black coloured piece as opposed to the usual silver. This sets it apart from most jewellery made of gold and silver, as gold does not usually appear in black and tarnish is usually avoided with silver.
Now that you know another metal that is used in jewellery, you can browse jewellery with more confidence in what you are looking for!
Ruthenium-finish Bracelet
Ruthenium-finish Bangle
Ruthenium-finish Earrings