Natural Spinel: Complete Guide for Trade, Jewelry, and Collections
This comprehensive guide provides everything you need to know about natural spinel, for trade partners, jewelers, and collectors alike.
Overview
Natural spinel is a gemstone that has long been overshadowed by its more famous counterparts, yet it is celebrated for its rich color spectrum, ranging from red to blue and even black. With a hardness of 7.5 to 8 on the Mohs scale, spinel is durable and suitable for various types of jewelry. This gemstone is often confused with ruby and sapphire due to its similar appearance, but its unique characteristics and rarity make it a sought-after choice for discerning collectors and jewelers. Understanding spinel's properties, sources, and market dynamics is crucial for anyone involved in its trade or collection.
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.