Since 1995, Moissanite has been in use as a gemstone. Moissanite was originally discovered in 1893 in a meteor by Henri Moissan (whom it was later named after).
Moissanite is a mineral that has an appearance very similar to diamond. In fact, when it was first discovered, Henri Moissan misidentified it as diamond. It wasn’t until 1904 that he realized it was different.
Until 1950, the only known source of Moissanite was meteorites. Eventually it was found in some mines, and then later labs started to synthesize it since it was so rare in nature.
Moissanite is harder than cubic zirconia, measuring in at 9.25 on the Mohs hardness scale (diamond is 10, CZ is 8.5-9).
Moissanite is 13% lighter than diamond by volume (which isn’t really an issue considering the size used for jewelry).
Moissanite has a property called “double refraction” which makes it more brilliant than diamond, which is only single refraction.
Moissanite is less expensive than diamond, but more expensive than CZ. Some moissanite have have a slightly green or gray appearance (as opposed to being colorless like high quality diamonds and cubic zirconia) that is sometimes apparent to the naked eye. For this reason, the particular moissanite gem you are buying should be viewed in person before you purchase it (or ordered from a vendor that allows returns).
A variety of jewelry, from earrings to necklaces to rings and engagement rings can be made of moissanite, and it continues to be a popular source of fake diamond.