Gemstone Coefficient of expansion

Akash asked about specific gravity. I would like to find a reference
which provides the coefficient of expansion for gemstones - both
genuine and “created.”

I have searched several times with different search engines on the
net, so far with no luck.

Thank you. Connie

Howdy Connie, A few years ago I did some of that research and found
as much at my local library in old mineralogy books as I did on the
web. The web had more of the properties of synthetics.

The info is out there if you dig. Beware of (IIRC) 10 to the -7
versus 10 to the -6 (or whatever) COEs. Older references use a
different notation. Also, materials exhibit diferent COE for
different temp ranges. Lok at the charts carefully. Also, I found one
reference that quoated a NEGATIVE COE for one xtal axis of
tourmaline, the other 2 axes were positive! Perhaps if you told us
what you were doing we could be more helpful. Carl 1 Lucky Texan