100% 925 Sterling Silver Marquise Cut Created Moissanite Gemstone. Moissanite--- Discovered in 1893 by a French scientist named Henri Moissan, who later won the Nobel Prize in Chemistry. He discovered microscopic particles of the gem that would eventually bear his name in Arizona, in a crater created by a meteorite that fell to Earth. He initially thought that he had discovered diamonds, but later determined that the crystals were composed of silicon carbide. Natural moissanite is incredibly rare, so moissanite available today is laboratory-created. After many years of trial and error, the particles Moissan discovered were successfully synthesized to produce what is now one of the world’s most scintillating gemstones.