Black Spinel and White Zircon (Set in Jewelry)
Magnesium Aluminum Oxide (Spinel Group) and Zirconium Silicate · Semi-Precious Gemstones
Crystal System
Cubic (Isometric) for Spinel; Tetragonal for Zircon. Habit is typically faceted into round brilliant cuts in this specimen.
Mineral Group
Oxides (Spinel) and Silicates (Zircon)
Chemical Formula
MgAl2O4 (Spinel) / ZrSiO4 (Zircon)
Formation Process
Spinel forms via contact metamorphism and in igneous rocks; Zircon forms as a primary crystallization product in igneous and metamorphic rocks.
About This Crystal
Composite jewelry piece featuring pave-set, opaque, jet-black faceted round gemstones (Black Spinel) contrasted with small, transparent, colorless faceted stones (White Zircons) exhibiting high luster.
Physical Characteristics
Black color with sub-adamantine luster, white streak, conchoidal fracture. Specific gravity: 3.6-4.1 (Spinel), 4.6-4.7 (Zircon). Non-fluorescent in black variety.
Optical Properties
Spinel is singly refractive (n=1.718); Zircon is doubly refractive (n=1.92-1.98) with high dispersion (fire) and strong birefringence.
Hardness & Durability
Origin Region
Thailand, Myanmar (Burma), Sri Lanka, and Cambodia; commonly found in alluvial gravel deposits.
Hardness & Durability
Mohs hardness 8 (Spinel), 7.5 (Zircon); Excellent wearability for rings due to high hardness and lack of cleavage in spinel.
Care & Maintenance
Clean with warm soapy water and a soft brush. While durable, avoid mechanical ultrasonic cleaners if stones have tiny inclusions or if the setting is delicate.
Rarity & Value
Common to Uncommon; Highly affordable alternative to Black Diamond. Value and price are dictated by the quality of the pavé setting and metal type (likely sterling silver).
Special Characteristics
The black spinel exhibits a deep, true black color without the secondary gray or brown tones seen in other black stones like onyx or tourmaline.
Lore & History
Historically often confused with black diamonds or tourmaline. Spinel is traditionally associated with revitalization and 're-energizing' according to gemstone lore; Zircons have been used since the Middle Ages as symbols of prosperity and wisdom.