Have you ever seen a piece of vintage jewelry which has what look like gunmetal gray rhinestones on it? If so, you are probably looking at a piece of jewelry which is made using what are known as marcasites.
A marcasite is is a type of stone, which is often used in sterling silver, and sometimes faceted. The natural mineral, shown on the right, has the same composition as pyrite (fool’s Gold) but has a different chemical structure. It is a gunmetal gray color with a shiny finish and is inserted in the same was as a rhinestone is.
The stone sometimes acquires a multi-colored tarnish may exist that is the result of oxidation. The stone has a luster and is opaque. Occasionally, a sulfur smell is detectable. When marcasites are used in jewelry, the result is a fashionable piece without the glitz of a rhinestone piece. Very understated and elegant.
You may have heard of fool’s gold. Marcasite is the white form of fools gold. Marcasite jewelry was especially fashionable in Victorian times. Jewelers usually describe marcasite as a bronze or gunmetal color, and the designs often resemble an "Art Deco" period. Contemporary designers continue to use the stone in modern jewelry pieces too.
One thing that appeals to me, after having seen so many rhinestone jewelry pieces with dulled or damaged rhinestones that have turned gray over time – a marcasite has that color to start with, so it isn’t able to do downhill as much!
Some jewelry is described as being made with marcasites when in fact it is actually an imitation variety. In the real thing, the marcasites are individual pieces of gemstones set into small settings, just the way a rhinestone is set. In a piece of jewelry made with faux marcasites, the design uses are made of small areas of metal which made to look like the genuine stone. The last picture below, a design by Kenneth Lane, shows faux marcasites. The other two are made with genuine marcasites.
Visit: Finishing Touch Vintage Jewelry
Photo credit of natural marcasite shown above: Geologynet.com