Marcasite boasts a natural ability to reflect light, and due to its brilliant lustre, jewellery designers often use it as a replacement for Diamond accents. The name is derived from the Arabic word for Pyrite, for which it is often mistaken, so much so that experts within the field of gemmology still discuss the issue at length.
As a pseudomorphic gem, the atoms replace themselves with other minerals so effectively they can change their whole identity (pseudomorph is a Latin word meaning “false shape”). Often the effect with Marcasite is noticeable on the surface of the gemstone as a thin skin of iron, which in turn creates a beautiful iridescent sheen.
It is also interesting that Marcasites with an iridescent oxide coating have been known to shine longer without polishing than non-coated Marcasites. Perhaps the gem is trying to protect itself when it pseudomorphs; in the same way an oyster or mollusc will when alien particles get into the shell - just a thought!
Marcasite was a popular gem in Victorian times and today tends to be associated with antique jewellery. This type of retro antique design is once again becoming fashionable and the demands for such pieces are only set to increase.
The gem is mined in several locations around the globe and a deposit of Marcasite with an intense lustre has been mined in the Swiss Alps since the late 1800’s. It has a rating of up to 6.5 on the Mohs scale and is therefore a reliable, durable gemstone that can last when worn on a frequent basis.
When it comes to origin, Switzerland is to Marcasite what Ceylon and Cashmere (Kashmir) are to Sapphire. No other origin yet discovered can match Swiss Marcasite in terms of surface cleanliness and lustre. Whilst Thailand may be the largest producer in the world of Marcasite jewellery, the quality of Marcasite mined within its own borders is nowhere near comparable with those unearthed in Switzerland.