Zirconia vs. strass crystal

Hi, can anyone tell the two materials apart ? I have a 12mm
brilliant cut stone which can be either of them. thanks SIMCHA from
HOLYLAND

Hi, can anyone tell the two materials apart ? I have a 12mm
brilliant cut stone which can be either of them. 

Glass shows stress patterns under a polariscope and has a
refractive index that’s fairly low and easily readable on a
refractomer (as opposed to C.Z., which is above the range of the
refractometer. If you look directly into the pavilion side of a
C.Z. with the table pointed at a light, you’ll often see the
entire pavilion lit up with an orange flash color. And under a
loupe, often you can see "flow’ lines in the glass. If not,
certainly you’ll see a much better and crisper polish and finish
on most C.Z.s than on the much softer glass. Cutting is often
different as well, since many glass stones are not actually a
full 56 facet cut. With a known example of each to compare to,
you should be able to see the difference fairly quickly, if it’s
not apparent with the comparison samples. There’s lots of ways,
really. But this should get you started…

Peter Rowe