Description
Natural sapphires are prized for their exceptional beauty and strength, making them a top choice for both jewelry and investment. These gemstones, typically blue but available in a range of colors, are formed deep within the Earth under high pressure and temperature. Their vibrant colors and remarkable clarity position them as a favorite among gem enthusiasts and jewelers alike.
Physical Properties and Specifications
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Chemical Composition: Al2O3 (Aluminum Oxide)
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Hardness: 9 on the Mohs scale
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Crystal System: Trigonal
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Refractive Index: 1.76 – 1.77
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Specific Gravity: 3.95 – 4.03
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Pleochroism: Weak to moderate (visible in some specimens)
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Fluorescence: Generally inert, but some may fluoresce under UV light
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Cleavage/Fracture: Indistinct cleavage; conchoidal fracture
Color and Quality Classifications
Available Color Ranges
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Primary Hues: Blue, yellow, pink, green
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Secondary Modifications: Violet, orange, gray
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Tone and Saturation Ranges: Light to dark tones; vivid saturation is most desirable
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Premium Colors: Deep blue, royal blue, and padparadscha (pink-orange)
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Commercial Grades: Commercial-grade sapphires are typically lighter hues or have visible inclusions
Clarity Characteristics
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Typical Inclusion Types: Rutile, silk, and crystal inclusions
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Clarity Grading Standards: Graded from eye-visible to eye-clean
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Source-Specific Features: Different sources produce varying inclusions
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Eye-Clean Criteria: Must be free of inclusions visible to the naked eye
Source Locations and Material
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Historic Sources: Kashmir, Burma (Myanmar)
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Current Production: Sri Lanka, Madagascar, Thailand
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Source-Specific Characteristics: Each location yields unique color and clarity traits
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Production Trends: Increasing interest in ethically sourced sapphires
