About the Magnesite “turquoise” used in the necklace:
This one-of-a-kind creation is made of magnesite stones. Magnesite is a beautiful stone. The most common color is white. Magnesite can have a web-like pattern that resembles the matrix in some turquoise. Magnesite has the same hardness and texture as turquoise. Even though magnesite is sometimes erroneously referred to as "chalk turquoise" or "white turquoise", the mineral is not related to turquoise since magnesite does not contain copper and is not a phosphate.
Since turquoise is getting rare, Magnesite is OFTEN dyed to resemble the ever more expensive turquoise nowadays . If dyed magnesite contains black or brown surface matrix, it is sometimes very difficult to distinguish it from real turquoise with matrix.
Many vendors have been known to pass off "turquoise" magnesite as stabilized turquoise. A rule of thumb: if the price of a turquoise necklace is too good to be true, it is most likely magnesite (or howlite). Most genuine turquoise is sold per gram, most often seen in rings, pendants, or as in cabochon.