1.4" Natural Polished Teal Turquoise Gemstone Mineral Specimen Cab
Location: Western Asia
Weight: 8.4 Grams
Dimensions: 1.4 Inches Long, 0.7 Inches Wide, 0.3 Inches Thick
The item pictured is one you will receive.
Overview of Turquoise
Turquoise is an opaque mineral that exhibits a blue-to-green color, primarily composed of copper and aluminum. Its chemical formula is CuAl6(PO4)4(OH)8·4H2O, indicating that it is a hydrous phosphate. This gemstone has been highly valued for thousands of years due to its distinctive hue and rarity, especially in finer grades.
Historical Significance
The name “turquoise” comes from the Old French word “turquois,” meaning “Turkish,” because the mineral was first introduced to Europe via the Ottoman Empire. Known since antiquity, Turquoise was referred to as “callais” by Pliny the Elder and as “chalchihuitl” by the Aztecs. This rich historical context highlights Turquoise’s enduring cultural, spiritual, and ornamental significance across civilizations, contributing to its lasting appeal as a gemstone.
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 involves a series of geological and chemical processes:
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Hydrothermal Activity: Hydrothermal fluids leach copper from host rocks, typically calc-alkaline intrusions rich in silica.
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Copper Deposition: The leached copper is redeposited in concentrated forms within fractures and joints of the rock.
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Meteoric Water Interaction: Rainwater or snowmelt infiltrates these deposits, oxidizing the copper minerals and resulting in the formation of Turquoise as a secondary mineral.
This process shows that Turquoise does not occur in its original copper-bearing rock but forms later through environmental and geochemical interactions, giving rise to its distinctive blue-to-green color and unique matrix patterns.
Market Value and Treatments
Turquoise’s value can vary significantly based on quality factors such as color saturation, matrix presence (the veining or patterning), and origin. High-quality turquoise from regions like Western Asia is particularly prized for its vibrant robin egg blue color. However, market dynamics have changed due to treatments (such as dyeing), imitations (synthetic versions), and enhancements that can affect its 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.
