Moissanite is a diamond simulant made of silicon carbide. A diamond simulant is a stone that has a similar appearance to a diamond, but is not a real diamond. It is very difficult to tell apart a diamond & moissanite, making moissanite a common diamond alternative.
Moissanite was originally discovered in a meteor crater in 1893 by scientist Henri Moissan. He mistakenly believed the crystals he found were diamonds. Naturally occurring moissanite is extremely rare. Because of this, most of the moissanite on the market is lab grown. It can take 2-3 months to create a single moissanite stone in a lab.
Most people cannot tell the difference between moissanite and diamonds. The GIA has even said that moissanite is “much closer to diamond in overall appearance and heft than any previous diamond imitation.”
One way to tell apart moissanite from diamond is to examine the stone’s brilliance and fire. Moissanite has more fire and brilliance than diamond – it isn’t as noticeable in smaller stones, but in stones over 5mm, it’s much more noticeable. Moissanite is known for its “disco ball” effect because rainbow light quickly flashes around the gem. However, looking at a stone’s fire and brilliance isn’t always a reliable way to differentiate the two because an expertly cut diamond will also have lots of fire and brilliance.
Does moissanite test as a real diamond?
There are diamond testers that rely on thermal conductivity and electrical conductivity. Because diamonds and moissanite conduct heat in a similar manner, it is possible for moissanite to read as a diamond on a diamond tester that relies on thermal conductivity. A diamond tester that tests stones on electrical conductivity shouldn’t confuse diamonds and moissanite because they conduct electricity differently.