Green turquoise, sometimes referred to as green turquoise cabochon, is a variety of turquoise that has a distinctive green color. Turquoise is an opaque, blue-to-green mineral that has been prized as a gemstone for thousands of years. While pure turquoise is blue, impurities in the stone can cause it to range from blue to blue-green to yellow-green in color.
What Causes the Green Color in Turquoise?
The green color in turquoise is caused by the presence of iron impurities in the gemstone’s composition. Turquoise consists of a hydrous phosphate of copper and aluminum called cuuprite. When iron mixes with the cuuprite during the gemstone’s formation, it causes turquoise to develop a greener hue.
The more iron present in the stone, the greener the turquoise becomes. Stones with a higher concentration of iron impurities exhibit a richer, deeper green color. Turquoise with less iron has a more blue to blue-green appearance. The intensity of the green color depends entirely on the amount of iron compounds present.
Difference Between Green Turquoise and Other Turquoise
In addition to the amount of iron content, there are some other key differences between green turquoise and more standard blue turquoise:
- Color: Green turquoise has a distinct yellow-green to emerald green color, while regular turquoise ranges from sky blue to pale blue-green.
- Source: Green turquoise more commonly comes from Iran, while American turquoise from Arizona and Nevada is usually blue to blue-green.
- Value: Natural green turquoise is rarer and more valuable than common blue turquoise.
- Hardness: Green turquoise tends to be slightly softer and porous compared to higher quality blue turquoise.
Where Does Green Turquoise Come From?
The largest source of natural green turquoise is Iran, which has produced the gemstone for thousands of years. The weathered volcanic rocks of Iran’s mountainous terrain contain higher amounts of iron, resulting in turquoise with a distinct green color.
Iranian green turquoise, sometimes referred to as “Persian turquoise,” is considered some of the finest in the world. Other sources of green turquoise include Afghanistan, Australia, and China. In the United States, green turquoise can occasionally be found in Nevada, New Mexico, and California, but American turquoise is typically bluer.
How is Green Turquoise Graded?
Green turquoise is graded based on the same criteria used to evaluate all turquoise gemstones. The main factors considered are:
- Color – Vivid green color is most desirable. Yellow-green is less valuable.
- Matrix – The veining and webbing in turquoise. Less visible matrix increases value.
- Clarity – Lack of flaws and inclusions increases clarity.
- Cut – Smooth, symmetrical cutting improves appearance.
- Carat weight – Heavier stones are more rare and valuable.
High quality green turquoise will have a vivid green color without matrix or inclusions. The gemstone will be cleanly cut and polished to showcase the rich green hue. However, completely flawless green turquoise is extremely rare.
How Much Does Green Turquoise Cost?
Natural green turquoise is one of the most expensive varieties of turquoise. High quality stones can cost upwards of $1000 per carat. The table below compares the price differences between natural green turquoise and more common blue turquoise:
| Type | Price Range |
|---|---|
| Natural Persian green turquoise | $500 – $2000 per carat |
| Natural American blue turquoise | $10 – $150 per carat |
There are a few reasons green turquoise demands a higher price:
- Rarity – Natural green turquoise is much less common than blue turquoise.
- Desirability – Vivid green color is considered more beautiful.
- Historical significance – Prized for thousands of years in Iran.
- Difficult to obtain – Limited supply from remote Iranian mines.
However, treated and stabilized green turquoise can sell for less, from $50 to $100 per carat. Imitation turquoise made from plastic resins are also inexpensive but lack the beauty and value of genuine gemstones.
Is Green Turquoise Valuable?
Natural green turquoise, especially Iranian stones, are among the most valuable varieties of turquoise. The vivid green color is highly coveted and Persian turquoise has been a status symbol for millennia. Green turquoise jewelry containing high quality gems can fetch high prices from collectors.
However, not all green turquoise is considered valuable. Low quality stones that are heavily included or have an unattractive color are not as prized. Heavily treated turquoise and fakes have very little worth compared to untreated natural gemstones.
Factors like carat weight, clarity, matrix patterns, and cut also determine green turquoise’s value. But the intensity and purity of the green color itself is one of the main drivers of its worth and price point.
How to Identify Green Turquoise
It takes a trained eye to identify untreated natural green turquoise. Here are some tips for spotting genuine stones:
- Color – Look for a vivid lime green to emerald green hue. Natural color should not be uniform.
- Matrix – Some black or brown veining indicates natural turquoise.
- Clarity – Natural stones will have some flaws. No visible inclusions suggests a treated stone.
- Luster – Natural turquoise has a waxy to dull luster. Fakes will have a plastic-like shine.
- Specific gravity – Real turquoise sinks in water. Fakes will float.
- Examine with magnification – Look for imperfections only found in natural gemstones.
The most valuable green turquoise will have a bright, slightly uneven green color with some matrix visible under magnification. While real turquoise is never 100% perfect, cheap fakes often look too perfect.
How to Care for Green Turquoise
While durable enough for jewelry, green turquoise requires some care to maintain its color and luster over time. Follow these tips:
- Avoid prolonged sun exposure – Can cause fading
- Take jewelry off before physical activities – Prevents damage
- Clean with mild soap and warm water – Avoid harsh chemicals
- Store properly – Keep away from other gems to prevent scratching
- Consider repolishing and resealing – Recommended every few years
With proper care, natural green turquoise can remain beautiful for many years. However, it’s softer than many gems so take precautions to prevent scratches and chips.
Popular Uses for Green Turquoise
Throughout history, green turquoise has been prized for its brilliant green hues. Here are some of the most popular uses of green turquoise today:
- Jewelry – Rings, necklaces, bracelets set with green turquoise gems.
- Talismans – Believed to have protective powers and used as good luck charms.
- Decorative objects – Figurines, vases, ornamental boxes made with carved turquoise.
- Inlay – Used ornamentally in furniture, musical instruments, art objects.
- Amulets – Mounted in silver or gold, worn for spiritual purposes.
- Mosaics – Turquoise tiles arranged in intricate patterns.
With its striking color, green turquoise has universal appeal across cultures. From ancient Iranian rulers to the Native Americans of the Southwest, green turquoise has long been a favorite gemstone for personal adornment and decorative arts.
Famous Green Turquoise Jewelry
Some of the most famous jewelry pieces in history have featured stunning green turquoise gems. A few legendary examples include:
- The Jean Schlumberger for Tiffany & Co. bird brooch – Designed in the 1950’s for the Duchess of Windsor using Persian turquoise and diamonds.
- Cartier Tutti Frutti style bracelets and necklaces – Intricately designed with carved green turquoise and gemstones.
- Van Cleef & Arpels Alhambra jewelry – Iconic line featuring quatrefoil shaped turquoise and mother of pearl.
- Native American squash blossom necklaces – Adorned with green turquoise beads and silverwork.
- Egyptian Revival jewelry – Recreating designs from ancient Egypt using turquoise stones.
These iconic turquoise jewelry pieces demonstrate the timeless appeal of green turquoise gems. The vibrant color makes it an eternally coveted stone.
How to Spot Fakes
With natural green turquoise scarce and expensive, fakes abound in the market. Here’s how to avoid counterfeit stones:
- Buy from reputable, trustworthy dealers with expertise in turquoise.
- Beware of prices that seem too good to be true.
- Learn to recognize artificial color and machine cut stones.
- Test specific gravity – real turquoise will sink in water.
- Examine for pores and inclusions visible under magnification.
- Ask for authentication from independent gemological labs like GIA.
Genuine natural green turquoise is increasingly rare. Always purchase from trusted sellers and ask questions to ensure authenticity.
How is Green Turquoise Formed?
Green turquoise forms through the same geological processes as other natural turquoise. A basic overview includes:
- Mineral rich waters flow through fractured host rocks, like granite, basalt or volcanic ash.
- Phosphates, copper, and aluminum leach from the rocks into the groundwater solution.
- The minerals crystallize and solidify in cavities and fractures in the rock, forming turquoise.
- Impurities like iron mix in, causing green turquoise to form.
- Weathering and erosion eventually exposes the turquoise deposits.
Turquoise ores require a unique balance of chemistry, minerals, water and environmental conditions to create the right elements for turquoise crystals to grow. The presence of iron during formation results in the signature green color.
Other Green Gemstones
While green turquoise is renowned for its striking hue, there are a few other green gemstones that offer similar allure:
- Emerald – The quintessential green gem, emeralds are a type of beryl.
- Peridot – A transparent olive-green gemstone formed by volcanic activity.
- Tsavorite – A rare vanadium-rich garnet with a vivid green color.
- Demantoid garnet – The premium green variety of garnet.
- Green tourmaline – Covering a range of green hues and intensities.
However, no green gem can quite match the distinctive opaque green shades of natural turquoise. The mottled matrix patterns within turquoise also set it apart from other uniform green stones.
Green Turquoise Treatments
With natural green turquoise scarce, the vast majority for sale has undergone treatments to improve color and durability. Common treatments include:
- Dyeing – Soaking in colored dye to change or enhance color.
- Waxing – Penetrating wax to stabilize porous stones.
- Resin coating – Surface sealing with clear plastic resins.
- Reconstitution – Crushing and reforming bonded powders.
- Stabilization – Impregnating with colorless polymer.
Treated stones may still have beauty but lack the value of untreated natural turquoise. Always get full disclosure about any modifications made to turquoise gems.
Green Turquoise vs. Jade
Green turquoise is sometimes confused with jade since both can exhibit similar green shades. Here’s how to tell them apart:
| Factor | Green Turquoise | Jade |
|---|---|---|
| Composition | Phosphate mineral | Silicate minerals |
| Hardness | 5-6 on Mohs scale | 6.5-7 on Mohs scale |
| Clarity | Opaque | Translucent to opaque |
| Luster | Waxy to dull | Greasy, vitreous |
| Structure | Amorphous | Crystalline |
While both are green gems, their chemical composition, physical structure and gemological properties clearly distinguish green turquoise and jade.
Geographic Sources of Green Turquoise
While found sporadically worldwide, here are the primary sources of natural green turquoise:
- Iran – Considered the premier source, Persian turquoise is prized for its vivid green color.
- Southwestern United States – Arizona, New Mexico and Nevada produce green turquoise, but more limited.
- China – A longtime producer primarily in Hubei, Anhui and Sichuan provinces.
- Tibet – Has produced greens for over 2000 years from localities like Derge and Nagari-Khorsum.
- Australia – Small deposits found sporadically throughout the continent.
While other localities occasionally produce green turquoise, Iran remains the gold standard, renowned for its distinct emerald green Persian turquoise.
Conclusion
With its striking green shades, turquoise occupies a unique place among colored gemstones. While pure turquoise is blue, natural impurities of iron during formation create the signature green hues prized by collectors and jewelry lovers worldwide. Sourced chiefly from Iran, natural green turquoise is a rare and valuable gemstone that has been coveted for millennia.
