1.2" Natural Polished Teal Turquoise Gemstone Mineral Specimen Cab

Location: Western Asia

Weight: 10.5 Grams

Dimensions: 1.2 Inches Long, 0.8 Inches Wide, 0.5 Inches Thick 

The item pictured is one you will receive.

Overview of Turquoise

Turquoise is an opaque mineral characterized by a blue-to-green coloration, primarily composed of copper and aluminum. Its chemical structure, CuAl6(PO4)4(OH)8·4H2O, classifies it as a hydrous phosphate. Esteemed for millennia, this gemstone’s unique color and scarcity—particularly in high-quality specimens—underscore its enduring value.

Historical Significance

The name “turquoise” derives from the Old French term “turquois,” meaning “Turkish,” reflecting its initial introduction to Europe via the Ottoman Empire. This gemstone has been acknowledged since ancient times—Pliny the Elder identified it as “callais,” while the Aztecs referred to it as “chalchihuitl.” Such historical references emphasize turquoise’s enduring cultural importance across diverse civilizations.

Properties of Turquoise

Turquoise possesses several notable physical properties:

• Color Variability: The color can range from white to powder blue, sky blue, blue-green, and even yellowish green. The blue coloration is primarily due to copper content, while iron impurities can lead to green hues.
• Hardness: On the Mohs scale, turquoise has a hardness of just under 6, which makes it softer than many other gemstones but still capable of taking a good polish.
• Luster and Transparency: It typically exhibits a waxy to subvitreous luster and is usually opaque, although some thin sections may be semitranslucent.
• Crystal Structure: Turquoise is classified as a cryptocrystalline mineral with a triclinic crystal system. It rarely forms single crystals; instead, it often appears in nodular or botryoidal forms.

Formation Process

The formation of turquoise deposits involves several geological processes:

1. Hydrothermal Activity: Initially, hydrothermal fluids leach copper from host rocks—typically calc-alkaline intrusions rich in silica.
2. Copper Deposition: The leached copper is redeposited in concentrated forms within fractures and joints in the rock.
3. Meteoric Water Interaction: As meteoric water (from rain or snowmelt) infiltrates these deposits, it oxidizes the copper minerals present, leading to the formation of turquoise as a secondary mineral.

This process indicates that turquoise does not occur in its original form within copper porphyry but rather develops later through environmental interactions.

Market Value and Treatments

The value of turquoise fluctuates greatly depending on factors like color intensity, matrix patterns, and geographic origin. Specimens from areas such as Western Asia are especially coveted for their vivid robin’s egg blue hue. However, market conditions have been influenced by treatments like dyeing, synthetic replicas, and other enhancements, which can impact the gemstone’s overall valuation.

In summary, turquoise remains a gemstone of great beauty and historical significance with unique properties that contribute to its desirability in jewelry and decorative arts.