1" Natural Polished Teal Turquoise Gemstone Mineral Specimen Cab
Location: Western Asia
Weight: 11 Grams
Dimensions: 1 Inch Long, 1 Inch Wide, 0.5 Inches Thick
The item pictured is one you will receive.
Overview of Turquoise
Turquoise is a captivating opaque mineral renowned for its vibrant blue-to-green color. Composed mainly 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 popular choice for jewelry, carvings, and decorative objects worldwide.
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
Turquoise forms through a combination of geological processes that transform copper-rich rocks into this prized gemstone:
-
Hydrothermal Activity: 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, veins, and joints in the rock.
-
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 demonstrates that turquoise does not occur in its original copper-bearing rock but forms later through environmental and geochemical interactions, giving rise to its characteristic blue-to-green color and unique veining 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.
