Colorless (D–Z scale) to fancy yellow, pink, blue, green, and brown, exhibiting adamantine luster and 0.044 dispersion.
Chemical formula
C (Isometric Crystalline Carbon)
Other Gemstones • Turquoise (Phosphate Group)
Turquoise (Feroza)
Robin's-egg sky blue to greenish-blue (when iron substitutes for aluminum), either clear unmatrixed or traversed by dark brown/black limonite, chert, or pyrite host-rock matrix.
CuAl₆(PO₄)₄(OH)₈ · 4H₂O (Hydrated Copper Aluminum Phosphate)Mohs 5.0 – 6.0 Mohs
Mineralogical & Gemological Profile
| Mineral Family | Other Gemstones |
|---|---|
| Mineral Species | Turquoise (Phosphate Group) |
| Gemological Variety | Natural Turquoise (Feroza) |
| Chemical Composition | CuAl₆(PO₄)₄(OH)₈ · 4H₂O (Hydrated Copper Aluminum Phosphate) |
| Crystal System | Triclinic (Cryptocrystalline aggregate) |
| Mohs Hardness | 5.0 – 6.0 Mohs |
| Specific Gravity | 2.60 – 2.90 |
| Refractive Index | 1.610 (Spot reading) |
Color Characteristics & Optical Behavior
Robin's-egg sky blue to greenish-blue (when iron substitutes for aluminum), either clear unmatrixed or traversed by dark brown/black limonite, chert, or pyrite host-rock matrix.
Geological Context & Pakistani / Global Localities
Forms in arid weathering zones of copper-rich volcanic and sedimentary rocks, most famously in Nishapur (Iran), Egypt (Sinai), China, and the American Southwest.
Collector Interest & Rarity Factors
Dense, high-hardness natural sky-blue Nishapur (Persian) turquoise ('Feroza') is prized throughout South and Central Asia.
Fine Jewelry Applications
Traditional silver and gold rings, cabochons, beads, and heritage jewelry.
Treatment Considerations & Disclosure
Polymer stabilization (to harden porous material) and dyed howlite/magnesite or reconstituted block imitations are extremely common in the global market. FADI Gems clearly discloses whether turquoise is natural untreated, stabilized, or composite.
Care & Cleaning Instructions
Turquoise is porous and sensitive to skin oils, perfumes, cosmetics, and soap residue. Wipe only with a clean, slightly damp cloth after wear; never use chemicals or ultrasonic cleaners.
Traditional Meaning
Traditional Symbolism & Cultural Heritage
Known as 'Feroza' (victorious) in Persian and Urdu traditions; worn for centuries across South Asia and the Middle East as a symbol of protection, serenity, and good fortune. December birthstone.
Note: Cultural and birthstone traditions are presented strictly as historical folklore, never as scientifically verified medical or metaphysical effects.
Other Gemstones
Related Entries
Naturally colorless, champagne-sherry (Skardu/Shigar pegmatites), golden-orange (Imperial), or rare natural cyclamen pink (Katlang, Pakistan); also vivid sky, Swiss,...
Chemical formula
Al₂SiO₄(F,OH)₂ (Aluminum Fluoro-Hydroxyl Silicate)
Electric Starlight blue, cinnamon-honey, imperial red, forest green, and diamond-bright colorless, exhibiting sub-adamantine luster and strong double refraction...
Chemical formula
ZrSiO₄ (Zirconium Silicate, with trace Hf, U, Th)