Turquoise, with its eye-catching variety of hues and affordable price, is a popular gemstone. Although most people are aware of turquoise’s beautiful blues and greens, few know what to look for when purchasing jewellery containing this stone. It is much simpler to choose a high-quality piece of jewellery if you are aware of the distinctions between treated and untreated stones and the grading systems used for each.
What Determines Turquoise’s Price
Formed in mineral-rich rocks, turquoise is a water-based stone. The stones’ distinctive hue is caused by the disproportionate concentration of one or more mineral elements. Turquoise, and hence the price of jewellery including this stone, is affected by the following.
Color
Although often blue, turquoise may also be found in a wide variety of other hues, from practically white to some extremely vibrant tones of yellow-green, depending on the region in which it was produced. Thin lines of the original matrix may be seen through the stone in certain turquoise specimens, creating a weblike pattern. “Spider-webbed” genuine turquoise jewelry is a term for this particular pattern.
Minerals that alter turquoise’s colour may also alter the stone’s toughness and quality. Thus, unlike the more common blue, rare and valuable stones are sometimes found in shades of extremely light blue or deep green.
Grades
A gemstone’s grade is a reliable indicator of its quality while shopping for turquoise. The finest gems may only be found in certain places and are often graded AA, AAA, or AAAA.
Tolerate a fine polish
Have AA or better webbing; turquoise of this quality is uncommon. The best quality turquoise for jewellery is AA-, A, B, or C. Jewelry made from materials of a lesser quality often costs less since they must be treated before use.
Care for Turquoise Jewelry
Most turquoise sold in jewellery shops has been processed in some manner unless it is labelled as natural. Inquire about the treatment history of the turquoise stones in any item you’re considering purchasing. Jewelers are required by law to declare any treatments done to stones sold.
The primary treatment modality is stabilisation. Epoxy resin or similar material is used to seal the pores of the stone, preventing the stone’s natural colour from fading over time.
Chemical treatments may also be used to improve the colour of stones. Untreated turquoise, depending on quality, may be quite costly, however treated turquoise is far more affordable.
Natural stone is softer than stabilised stone, so that’s how you can tell the difference. And since the resin sets the colour, it will never fade. However, the hue of natural stone may shift over time. Also, unlike stabilised stone, natural stone is porous and may soak up liquids and oils.
Hardness
When put next to harder stones like diamonds and sapphires, turquoise’s porosity and pliability pale in comparison. On the Mohs scale, where diamond is at a perfect 10 and turquoise is at a more modest 2, a diamond is clearly the hardest natural substance known. A score of 2 indicates that the stone is very porous and soft, and will need treatment. Jewelry grade turquoise (6 or above) does not need to be treated before being worn.
Pricing
Individual pieces of turquoise may have a wide range in price due to differences in colour, grade, and quality. Stones may cost anything from a few dollars per carat to upwards of $80 per carat if they are rare, large, intensely coloured, or of very high hardness.
