If you can find an old copy of the Turquoise Blue Book, I think it
would answer your question. We used to deal in turquoise for the most
part a few years ago. We always carried a copy to our shows. Many
of the older mines had green or blue green turquoise
but as to color, it is usually a personal preference. Some people
call the King Mine which was in Manassa Colorado the "cadillac"
of turquoise but that is only some
If you can access the lapidairy journal website, it might have some
tidbits for you. I have heard of treated stones, but usually it is to
make cheap turquoise “look good” Howlite is also treated and dishonest
people have sold it as turquoise. The old number 8 mine near Tonopah
Nevada produced what is some of the most beautiful spider webbed
turquiose it ranged from blue to green but more was green than blue.
Mine has been closed for many years. Carico Lake Turquoise is also a
beautiful green, for the most part, mostly a blue-green which is more
green than blue. More later