1.1" Natural Polished Teal Turquoise Gemstone Mineral Specimen Cab

Location: Western Asia

Weight: 9.7 Grams

Dimensions: 1.1 Inches Long, 0.8 Inches Wide, 0.4 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 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.

Turquoise – Physical Properties

Turquoise exhibits several distinctive physical properties that make it a unique and desirable gemstone:

1. Color Variability: Turquoise ranges from white to powder blue, sky blue, blue-green, and yellowish-green. Its vibrant blue tones are primarily due to copper content, while iron impurities contribute to green shades.

2. Hardness: With a Mohs hardness of just under 6, Turquoise is softer than many gemstones but can still achieve a good polish, making it suitable for jewelry and carvings.

3. Luster and Transparency: Turquoise typically shows a waxy to subvitreous luster and is mostly opaque, though thin sections may appear semitranslucent.

4. Crystal Structure: Classified as a cryptocrystalline mineral with a triclinic crystal system, Turquoise rarely forms single crystals and often appears in nodular or botryoidal forms.

These physical characteristics, along with its unique color and historical significance, make Turquoise highly valued in jewelry, decorative arts, and collector markets.

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

Turquoise – Value Factors and Summary

The value of Turquoise depends on several key quality factors, including color saturation, matrix patterns (veining), and origin. High-quality turquoise, especially from regions like Western Asia, is highly prized for its vivid robin’s egg blue color. However, treatments such as dyeing, synthetic imitations, and other enhancements can influence its market value and authenticity.

In summary, Turquoise remains a gemstone of exceptional beauty and historical significance. Its unique color, physical properties, and cultural heritage make it highly desirable for jewelry, carvings, and decorative arts, as well as a favorite among collectors and enthusiasts worldwide.