Well, the first post went thru so I'll try again.
I do a lot of turquoise work. For a silver worker I probably have
more turquoise rough than the law allows. Both stabilized and
I would like to use all natural turquoise when I cut a stone for
someone. But, natural rough these days (unfortunately) is usually
half or more chalk.
You can cut a stone from one end of a nodule that is hard as can be
and will take a high polish. The other end of the same baby fist
sized nodule may yield a stone that will fall apart in your hand.
Hard, solid rough is still available for a price. An unreasonable
price as far as I am concerned.
Stabilizing is usually done with epoxy resins. These can be detected
with a hot needle test if necessary.
Stabilizing turquoise is a way to still get some of the old
recognized turquoise into use. It is easier to work and will not
change color as readily as natural turquoise that is marginal. Like,
takes a high shine but is porous enough to absorb nastys.
I have some Sleeping Beauty turquoise that I bought 50 years ago
that looks the same today that it looked then. I won't handle that
Sleeping Beauty turquoise today because it is all 'Enhanced', as far
as I am concerned, with a proprietary process that cannot be easily
detected except by an experienced cutter. Besides, it is usually all
blue and doesn't sell very well. People seem to want stuff with
matrix because "they can't put that stuff in there".
Don't be afraid of stabilized turquoise, or heat treated sapphire.