Turquoise Quality Factors
Typically, whether a fashioned turquoise meets the ideal or departs from it, it’s judged on three basic qualities—its colour, its texture and the presence or absence of matrix.
The most-prized turquoise colour is an even, intense, medium blue. But some consumers prefer a greenish blue, and some contemporary designers actively seek avocado and lime green turquoise.
Turquoise can be semitranslucent to opaque, with a colour that usually ranges from light to medium blue or greenish blue. It’s often mottled, and sometimes has dark splotches. It might also have veins of matrix running through it (matrix is a remnant of its surrounding rock). The material known as spiderweb turquoise contains fine seams of matrix that form attractive web-like patterns.
The most valuable turquoise is an even medium blue, with no matrix and the ability to take a good polish.
Turquoise is most often fashioned as a cabochon. The smoothly rounded dome shape sets off turquoise’s colour, texture and any matrix beautifully. In addition, manufacturers and artisans fashion turquoise rough into round or oblong beads for strand necklaces, and into small, flat pieces that are popular in jewellery inlays. Some top-colour blue turquoise is engraved with Persian or Arabic inscriptions, inlaid with gold. Other rough material might be tumbled into “nuggets".
Turquoise is available in a wide range of sizes. All sizes, even very small ones, are used in Native American jewellery, and large sizes have been popular for carvings. For any size, the quality and evenness of the colour is the overriding value factor.