Turquoise Buying Guide
by Shewata Dhanuka
Turquoise was first mined in Iran (earlier known as Persia). For many years it was the prime source but now all its mines are depleted. Today, this opaque beauty in large quantity is received from Mexico, China and United States (Arizona and California). It is also procured from Australia, Afghanistan, Chile, Israel, Tanzania, Tibet and Turkey.
Turquoise is a treasured gemstone for many years. In every century people have been using it for making beautiful jewelry items. It is important part of Southwestern American jewelry. It can be set into any material like gold, silver or oxidized metal. It gets very well paired with other precious and semi precious gems. Oxidized metal jewelry consisting turquoise and other gemstone gives unique antique look that is liked by many jewelry lovers around the world. It is jewelry stone most in demand in many parts of the universe such United States, India etc.
It is said to be the oldest found gemstone. Many ancient manuscripts of different countries mentions the beliefs associated with turquoise. It is believed to possess medicinal properties that heal chronic diseases and other properties that bring prosperity and growth. At present, it is widely used in fashion jewelry as an icon of style and youth. Bracelets, rings, earrings, pendent, belts and other items consisting of turquoise gemstone and beads are popular among all the ages.
It is assigned as December birthstone and 5th anniversary gemstone. It is a non-transparent gemstone cut into all the possible shapes like pear, heart, round and flower cut. Oval shape is most common and easily available. This gemstone comes in different colours and quality. Market offers three distinct varieties of turquoise viz. natural, treated or enhanced and laboratory created or imitation. These three further are available in different colours with or without spider web matrix. As such there are no standard guideline for buying turquoise. However, this article gives all the necessary information about source, colour, quality and care about this amazing gem.
Turquoise was first mined in Iran (earlier known as Persia). For many years it was the prime source but now all its mines are depleted. Today, this opaque beauty in large quantity is received from Mexico, China and United States (Arizona and California). It is also procured from Australia, Afghanistan, Chile, Israel, Tanzania, Tibet and Turkey. It is found in association with copper mining and also considered as one of the by-product. It is formed when a chemical reaction takes place after water slowly enters into the rocks containing copper, aluminum and other phosphates. Usually, rough turquoise is very soft & porous and used for jewelry making only after it is treated. Few natural hard turquoise are also produced in nature, found near copper deposits near earth surface where it gets dry.
There is no perfect colour for turquoise. The colour is dependent upon the chemical composition of the rocks. This is the reason why no two turquoise gems shall have identical colour. The colour would range between pale blue to bright green. The blue colour is due to the presence of copper in the gem, green shade appears because of more content of iron or aluminum and yellowish green colour comes from the zinc traces. These rare combinations of different elements are responsible for the varied colours of turquoise. The intense pure blue colour is very rare therefore is priced most. Then bluish green and green shades are valued. Finally yellowish green shades are considered as poorest quality and thus priced least.
Turquoise occurs in one colour while sometimes it consists of few lines or veins of different colour. These veins are referred as spider web matrix. It appears on the surface of the gemstone due to the uneven distribution of elements present in the composition. Same as the colour of turquoise is different, so is the colour of the lines/veins on it. Veins/lines can be black, yellow or brown in colour. These lines would not be in any fixed pattern. It is completely natural so every gemstone is different. Pure single colour gems are priced more than those consisting the spider web matrix. However, intense blue colour with the spider web matrix is priced more than the pale yellowish green shade.
Like unique and varied appearance, turquoise is treated in many ways. Less than 10% natural turquoise is obtained from the mines around the world. These are high quality stones that are naturally hard and do not require any treatment. It is used for jewelry making in its natural state after cutting and polishing. No artificial changes are made. Natural turquoise is prone to colour change with years rolling, same as that of treated gems. Natural turquoise without spider web matrix is seldom found and fetches maximum price.
Experts specify that almost 80-90% of turquoise available in the market is treated. As mentioned earlier, rough turquoise is too soft and for making any jewelry item it needs to be turned hard through a suitable treatment. The enhanced or treated gems are different from the synthetic, man made, artificially created gems in the laboratory. The treated gems are also found in mines same as natural turquoise, but these undergo a treatment process in order to improve the colour, hardness, durability and availability. For example- Turquoise from China is always enhanced as it is too soft and it remains in high demand. Treated gems are equally marvelous but are priced less than the untreated gems.
The treatments are performed for stabilization and enhancement of the gemstone. There are different methods used for different purpose. To enhance the colour, ‘colour treat’ method is used in which epoxy resin along with the colour is injected into the pores of the gemstone. The colour gets stabilized and remains unchanged for a longer duration. The Chinese turquoise is turned hard by the process in which liquid plastic is injected in the stone. There is yet another method ‘ clear treat’ used for turning soft gem into hard. In this method only epoxy resin is inserted inside the gem to stabilize it. As a result colour remains same while gemstone get hard.
Other than the treated turquoise many imitations are also sold as natural turquoise. Buyer should be careful while buying. These are plastic coated or waxed. Therefore, experts recommend to buy turquoise gemstone and jewelry only from the reputed and knowledgeable seller. Always seek written guarantee and certificate before making the final payments.
Turquoise is the most delicate beauty. It is between 5-6 Mohs on the hardness scale and requires maximum care than any other semi precious stone. It should be protected against the scratches and sharp blows. It should not be stored with other hard gemstone rather store in jewelry box lined with velvet or soft cloth.
Being porous in nature, it is absorbent to all sorts of liquids. It must be prevented from direct exposure to hot water, harsh chemicals, cosmetics, oils, perfumes and even the perspiration else it results in colour change or might become dull. Clean turquoise consisting jewelry with mild soapy water and wipe it fully with a soft cloth. It should be completely dry before keeping it in the jewelry box. Ultrasonic jewelry cleaner must be avoided totally.
All the turquoise gems are susceptible to colour change and getting dull with the passage of time. However, this doesn’t affect the demand of the stone in anyway. People wearing turquoise jewelry get attached with the stone mentally. Thus, wearing this exquisite and sophisticated gem becomes their passion.