Gemology: M is for ...
We've reached the halfway point of our Gemology guide! This week we bring you gemstones beginning with M... Mabe Pearls, Malachite, Marcasite, Maw Sit Sit, Moldavite, Moonstone, Morganite, Moonstone, Mother-of-Pearl and Mystic Topaz.
Mabe Pearls, like all pearls, are an organic gemstone. Most pearls grow from an irritant on the flesh of an oyster or mollusc. The mollusc will then secrete a 'nacre' all over the irritant to form the pearl. The difference with mabe pearls is that the irritant is not on the flesh of the mollusc, but on the inner surface of the shell. This results in a dome shaped pearl with a flat bottom. Depending on how long the pearl has had to form, it could be an irregular blister shape, or a perfect rounded hemisphere.
Malachite is actually the same substance that forms the green 'rust' on copper, but in its gemstone form it can be polished into beautiful cabochons. Malachite can be found in slabs large enough to carve into statues or even use as a gorgeous green bench top! Ancient Greeks, Romans and Egyptians prized malachite for jewellery, and would even grind it to a powder for eye shadow. There are a number of myths and legends surrounding the humble malachite: in the middle ages it was believed that malachite would protect the wearer from the evil eye; Russian legends stated that drinking from a malachite cup would enable a person to communicate with animals; and many cultures believe malachite can attract money.
Marcasite Marcasite is an iron disulphide (sorry for getting technical on you!), but the marcasite in marcasite jewellery isn't marcasite at all - it's a different form of iron disulphide called Pyrite (also known as 'Fool's Gold'). Marcasite is unstable and prone to decomposition that forms a chalky coating, so it really isn't suitable for jewellery at all. Pyrite, on the other hand, is stronger and more stable, and forms a shiny metallic golden shimmer, which is highly desirable for jewellery use. 'Marcasite' was very popular in jewellery in Victorian times when black became the most fashionable colour following Prince Albert's death, but Grandma's antique marcasite jewellery is most likely to be fool's gold.