To simulate:
To have or take on the appearance, form, or sound of; imitate
Synthetic:
a. Not natural or genuine; artificial or contrived: “counterfeit
rhetoric that flourishes when passions are synthetic” George F.
Will. b. Prepared or made artificially
So simulant gemstones are gems made to look like or imitate certain
natural gems, so CZ is a simulant.
Synthetic are not natural and are prepared artificially but are
chemically identical to their natural counterparts. So lab-made
corundum is synthetic.
I’ve only just my head around the difference myself!
Helen
UK
And my understanding is that even a real or synthetic gem can be a
simulant if it’s used to impersonate some other kind of gem. So
something like synthetic spinel, which can be given different colors,
can actually function as a simulant for a variety of birthstones.
Basically if a gem is marketed as anything other than what it really
is, it’s a simulant regardless of whether the gem itself is natural
or synthetic. On the other hand, if that same synthetic spinel was
actually to be marketed as “spinel”, then it should also be disclosed
as being synthetic. Since it isn’t impersonating some other gem, it
isn’t functioning as a simulant in that case.
Chris