There are several ways to identify a moissanite:
1. Moissanite is doubly refractive. This means that when a ray of light passes through moissanite, it is slowed, bent and split in two. Using a loupe of 10x magnification, examine the cutlet through the crown facet. Determine if there is a doubling of facet junctions. This doubling will not be apparent when viewed through the table (top of the gemstone) via the optic axis.
2. Under 10x magnification, examine the gemstone for needle-like inclusions, typically perpendicular to the table facet.
3. Examine for specific refractive and gravity indices.
4. Have a jeweler or gemologist use a testing device specifically designed to distinguish moissanite from diamond. Testers that rely on thermal conductivity can mistake a moissanite for a diamond as these two gemstones conduct heat similarly. Use testers that rely on electrical conductivity to distinguish the two.
Florentine moissanites, if 0.80ct Diamond Equivalent Weight (DEW) or larger, have been laser engraved with information to aid in confirming that your gemstone is authentic Florentine moissanite.