Cobalt Blue Glass (Man-made)
Amorphous Silica glass with Cobalt oxide dopant · Decorative Stone / Simulant Crystal
Crystal System
Amorphous (Non-crystalline); lacks an internal ordered structure. Habit is man-made heart shape.
Mineral Group
Silicate glassware (Silicates class, though technically a non-mineraloid mineral substance)
Chemical Formula
SiO2 + Na2O + CaO + CoO (trace)
Formation Process
Industrial melting of silica sand, soda ash, and limestone at high temperatures, then rapid cooling to prevent crystallization.
About This Crystal
Deep cobalt blue, transparent heart-shaped cabochon. Exhibits a vitreous (glassy) luster with a smooth, polished surface and high clarity without natural inclusions.
Physical Characteristics
Color: Cobalt blue; Streak: White; Cleavage: None; Fracture: Conchoidal; Density: 2.4–2.8 g/cm³; Brittle tenacity; Often inert or red under Chelsea filter.
Optical Properties
Isotropic (Singly refractive); Refractive Index: 1.47-1.52; No pleochroism; No birefringence; High transparency.
Hardness & Durability
Origin Region
Industrial manufacture; global production (common in glass factories). Not geologically sourced.
Hardness & Durability
Mohs hardness 5 to 5.5; relatively soft compared to gemstones; poor toughness; susceptible to scratching and chipping.
Care & Maintenance
Wash with warm soapy water; avoid abrasive cleaners or ultrasonics; store separately to prevent scratching by harder stones like quartz.
Rarity & Value
Common/Abundant; low value; used primarily for costume jewelry and decorative purposes.
Special Characteristics
Occasional gas bubbles (seed bubbles) or swirl marks (striae) may be visible under magnification; lacks natural mineral inclusions.
Lore & History
Blue glass has been used since ancient Egypt and Rome to simulate lapis lazuli and sapphire. Modernly associated with the throat chakra and communication.