IDing Simulants/Synthetics

[HDer]

So I recently bought some cheap cufflinks that were sold to me as having sapphires, but I think might just be glass or CZ. Anyone have any idea of how to ID the stones just using magnification?

 

[Bron357]

Usually with a good Loupe (ie x 20 magnification) you can normally see little round bubbles which are indicative of coloured glass. Man made sapphire is harder to ID while in a setting as you would be looking for curved growth lines (called striae) and you need to be able to turn the gem through 360.
Other signs of glass are less than “crisp” facets ie made in a mould instead of actually facetted and also facet abrasions.

 

[HDer]

So I need some more practice to see the round bubbles, but the cut looks a little weird to me. Most round cuts I've seen for diamonds and sapphires are an octagon with triangles off each edge, whereas this looks like an octagon with trapezoids coming off of each edge. Some of the pictures also make it look like the "sapphire" is glued in.