I don't know if this helps, but I found the info on the "About Turquoise" tab included with item J295875 a sleeping beauty ring. I imagine it is also included with other turquoise items.
"While Turquoise is naturally beautiful, it tends to be porous and sometimes brittle. Most Turquoise is treated by one of three methods to enhance durability and allow for a better polish:
Impregnated with colorless resin or plastic
Proprietary Zachery Method
Luster Enhancement
Questions you might have regarding Turquoise:
Is turquoise jewelry sold on QVC genuine and natural?
Yes, it is.
Does QVC accept composite, reconstituted or reconstructed turquoise?
QVC does not currently accept composite, reconstituted, or reconstructed turquoise.
Is turquoise in the jewelry sold on QVC color treated?
Dye and other coloring agents are not acceptable as treatments.
Is the turquoise sold in QVC's jewelry brittle?
While some Turquoise is naturally beautiful, it tends to be porous and sometimes brittle. The QVC approved treatments enhances durability and allows for a better polish.
What are the treatments that QVC accepts?
QVC accepts only the following stable treatments:
Impregnated with colorless resin or plastic
Proprietary Zachery Method
Luster Enhancement
Why is the Sleeping Beauty Turquoise almost free of matrix or markings in the stone?
For Sleeping Beauty Turquoise, we closely monitor the range of blue color and the level of mottling, matrix and markings we will accept. Sleeping Beauty Turquoise can have all of these markings in the stone, but QVC currently accepts only Sleeping Beauty Turquoise that is free of markings."