1.1" Natural Polished Teal Turquoise Gemstone Mineral Specimen Cab
Location: Western Asia
Weight: 10.6 Grams
Dimensions: 1.1 Inches Long, 1 Inch Wide, 0.4 Inches Thick
The item pictured is one you will receive.
Overview of Turquoise
Turquoise is a captivating opaque mineral known for its vibrant blue-to-green color. Composed primarily of copper and aluminum, its chemical formula is CuAl6(PO4)4(OH)8·4H2O, classifying it as a hydrous phosphate. This gemstone has been highly valued for thousands of years for its distinctive hue, rarity, and the beauty of higher-quality specimens. Its unique color and historical significance make Turquoise a prized choice for jewelry, carvings, and decorative objects.
Historical Significance
The term “turquoise” originates from the Old French word “turquois,” meaning “Turkish,” as the mineral was first introduced to Europe through the Ottoman Empire. The gemstone has been known since antiquity; Pliny the Elder referred to it as “callais,” and it was recognized by the Aztecs as “chalchihuitl.” This historical context highlights turquoise’s long-standing cultural significance across various 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:
- Hydrothermal Activity: Initially, hydrothermal fluids leach copper from host rocks—typically calc-alkaline intrusions rich in silica.
- Copper Deposition: The leached copper is redeposited in concentrated forms within fractures and joints in the rock.
- 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 varies widely depending on quality factors such as color saturation, matrix patterns (veining), and origin. High-quality stones, particularly from regions like Western Asia, are especially prized for their vibrant robin’s egg blue hue. Modern market dynamics, however, are influenced by treatments such as dyeing, synthetic imitations, and enhancements, all of which can affect the gemstone’s perceived value.
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.