Methods of Identifying.

One carat created moissanite and diamond in water with a high intensity light displaying the refractive index (RI) and dispersion. The higher dispersion and RI of moissanite is shown with the ring of "specks" or "flames" extending beyond that for diamond.
 
The Tester Model 590 distinguishes between diamond and created moissanite by testing for the absorption of ultraviolet light only after using a standard thermal diamond probe. Diamond will transmit the UV light, while moissanite will absorb at these wavelengths. The Tester Model 590 should be used only after one uses a standard thermal probe to identify that a gemstone tests as a diamond.
 
This photo, taken at 200X, shows moissanite's double refraction. Moissanite is cut with the table perpendicular to the "c" axis; consequently, by looking through the table of a stone, one is viewing the singly refractive direction which does not produce doubling. Viewing through the crown or pavilion facets is recommended. Diamond is singly refractive, and therefore does not show doubling.
 
By using a 10X loupe to look through the crown or pavilion facets of a round brilliant cut stone (for example), one can see quite easily the double image of back facet edges -- almost like "tram lines" that must be parallel.
 
This photo, at 10X magnification, shows needle or tube-like inclusions. These inclusions are typically straight and parallel to the "C" axis. Charles & Colvard continues to work to eliminate such inclusions.
 
There is some variability in these needle or tube-like inclusions. In this photo, at 50X, you can see one variation of the needle or tube-like inclusions.
 
As a general rule, Charles & Colvard polishes the girdles of moissanite jewels (not faceted). Here is an example at 50X. This is an indicator of moissanite and not a definitive method of identification.