Use a diamond tester - this apparatus uses heat to see if the stone is diamond. Diamond dissipates heat very quickly, so this tool is very quick and effective; | |
The "Dot" test - draw a dot on a piece of paper and place a loose diamond (table down, culet up) on the dot. If the dot is clear (visible), the stone is most likely a simulant, such as CZ. A diamond refracts the light and thus the dot should not be visible. Please note that some baguettes and marquises may still show the dot due to it | |
Wear test - Diamonds are very strong and only wear or abrade when they clash with other diamonds. Simulants, such as CZ, on the other hand, are softer and abrade more easily. So, if you have a very worn stone (lots of little nicks and chip, especially around the culet and on the pavilion facets (leading down to the culet), then the chances are you have a stimulant. | |
The "flash" test - again, with a loose stone, as you pivot the stone under light, the pavilion (underside) might flash orange over most facets (synthetic cubic zirconia) or blue and violet (yttrium aluminium garnet) | |
Doubling" - when viewed under 10x magnification, synthetic moissanite, synthetic rutile and zircon will show "doubling." As you look through the table and rock the stone, the pavilion facet edges (underneath) and the culet will appear double (i.e. there are two of each of them). Diamonds are singly refractive, while moissanite is doubly refractive. |