Amber is not technically a stone

Was: Speed Brite ionic cleaner

Amber is not technically a stone...and technically is a soluble
material (i.e. it disagrees with acetone & alcohol)... 
A test to separate fossil amber from copal, which is not
fossilized, is to use acetone. Fossil amber does not react to
acetone, and copal gets sticky. 

I’ve used denatured alcohol as a test for copal; it also gets sticky
when rubbed with alcohol. In fact I’ve made a shellac-like varnish
by dissolving copal in alcohol. So I got all excited when I read that
amber was soluble in acetone, thinking I could make a similar
amber-based varnish. I tried an experiment, putting some amber
shavings in a glass jar with some acetone overnight. Alas, my results
confirmed Richard’s opinion above - there was no significant
dissolution of the amber shavings that I could observe. As far as I
know, the only solvent for amber is ether, which I don’t want to mess
around with…

Andrew Werby

Alas, my results confirmed Richard's opinion above - there was no
significant dissolution of the amber shavings that I could observe. 

Not an opinion, Gemological training, G.I.A., 1977

Richard Hart G.G.
Denver, Co.

Amber is really “tree sap” that’s how insects got caught inside this
hardened gooey stuff. not good friends with filing or any aggresive
cleaning…Gerry !

I believe the technical term for amber is: amorphous solid.

Christopher L. Johnston