Intense electric royal to neon blue caused by trace divalent cobalt (Co2+), distinct from common grayish-blue iron-colored spinel.
Chemical formula
MgAl₂O₄ + Co²⁺ (± Fe²⁺)
Spinel • Spinel
Red Spinel
Pure crimson red,brick-red, to traffic-light red, colored by chromium substituting for aluminum with strong red organ-pipe fluorescence under UV light.
MgAl₂O₄ + Cr³⁺ (Magnesium Aluminum Oxide with Chromium)Mohs 8.0 Mohs
Mineralogical & Gemological Profile
| Mineral Family | Spinel |
|---|---|
| Mineral Species | Spinel |
| Gemological Variety | Red Spinel |
| Chemical Composition | MgAl₂O₄ + Cr³⁺ (Magnesium Aluminum Oxide with Chromium) |
| Crystal System | Isometric (Octahedral and macle twins) |
| Mohs Hardness | 8.0 Mohs |
| Specific Gravity | 3.58 – 3.64 |
| Refractive Index | 1.718 (Singly refractive; Dispersion 0.020) |
Color Characteristics & Optical Behavior
Pure crimson red,brick-red, to traffic-light red, colored by chromium substituting for aluminum with strong red organ-pipe fluorescence under UV light.
Geological Context & Pakistani / Global Localities
Forms in metamorphosed dolomitic marbles in Myanmar (Mogok), Tajikistan (Kuh-i-Lal / Badakhshan), Vietnam (Luc Yen), Tanzania (Mahenge), and northern Pakistan (Hunza marble belt).
Collector Interest & Rarity Factors
Singly refractive optical behavior gives red spinel crisp, unmuddled brilliance, and octahedral 'spinel law' twins on marble matrix are classic mineral specimens.
Fine Jewelry Applications
Exceptional durability (8.0 Mohs, no cleavage) makes red spinel a premier choice for engagement rings and heirloom jewelry.
Treatment Considerations & Disclosure
The vast majority of red spinels in the global market are completely untreated.
Care & Cleaning Instructions
Clean with warm soapy water and a soft brush.
Traditional Meaning
Traditional Symbolism & Cultural Heritage
Historically treasured by Mughal Emperors (who inscribed giant Badakhshan spinels with royal titles) as a symbol of sovereignty and vitality. Official August birthstone.
Note: Cultural and birthstone traditions are presented strictly as historical folklore, never as scientifically verified medical or metaphysical effects.
Spinel
Related Entries
Glowing neon hot-pink to electric pinkish-red with virtually zero dark tone ('no dark side'), caused by high chromium...
Chemical formula
MgAl₂O₄ + Cr³⁺ (Very low Iron content)