Physical Properties and Specifications

• Chemical Composition: MgAl₂O₄

• Hardness: 7.5 – 8 on the Mohs scale

• Crystal System: Cubic

• Refractive Index: 1.718 – 1.730

• Specific Gravity: 3.58 – 3.62

• Pleochroism: Weak, typically showing slight color variation

• Fluorescence: Generally inert, but can show weak fluorescence

• Cleavage/Fracture: Perfect octahedral cleavage, conchoidal fracture

Color and Quality Classifications

Available Color Ranges

• Primary hues: Red, blue, pink, orange, purple, and black

• Secondary modifications: Brown, gray, and green shades

• Tone and saturation ranges: Light to dark tones with vivid saturation

• Premium colors: Bright red, cobalt blue, and vivid pink

• Commercial grades: Light shades and less saturated colors

Clarity Characteristics

• Typical inclusion types: Needle-like inclusions, color zoning

• Clarity grading standards: Eye-clean to included

• Source-specific features: Unique inclusions that may indicate origin

• Eye-clean criteria: No visible inclusions to the naked eye

Source Locations and Material

Historic sources

• Myanmar (Burma), Sri Lanka, Afghanistan, and Tanzania

Current production

• Significant production is currently from Myanmar, Tanzania, and Vietnam.

Source-specific characteristics

• Each location imparts distinct characteristics in color and clarity.

Production trends

• Increasing demand for spinel due to its unique colors and growing recognition in the jewelry market.