Blue Obsidian
Volcanic Glass var. Blue Obsidian · Decorative Stone
Crystal System
Amorphous (Non-crystalline)
Mineral Group
Mineraloid
Chemical Formula
SiO2 with various impurities
Formation Process
Extrusive igneous process where felsic lava cools rapidly without sufficient time for crystal growth
About This Crystal
A polished spherical specimen displaying a vibrant turquoise to cyan blue color with internal swirls and minor inclusions, exhibiting a glassy, vitreous luster and semi-translucent transparency.
Physical Characteristics
Vivid blue body color, white streak, no cleavage, distinctly conchoidal fracture, specific gravity around 2.35 to 2.45, brittle tenacity, non-magnetic, and generally inert under ultraviolet light.
Optical Properties
Singly refractive (isotropic) with a refractive index of approximately 1.48 to 1.51, no pleochroism.
Hardness & Durability
Origin Region
Mexico, USA, and various volcanic regions worldwide
Hardness & Durability
Mohs hardness of 5 to 5.5, brittle toughness, sensitive to sharp impacts and scratches, moderate wearability for jewelry if protected in settings.
Care & Maintenance
Clean with warm soapy water and a soft cloth, avoid ultrasonic and steam cleaners, store separately to prevent scratching, and protect from harsh acids and prolonged direct sunlight.
Rarity & Value
Common, though natural blue obsidian is extremely rare and most commercial blue obsidian is man-made glass; affordable price range for polished spheres.
Special Characteristics
Displays sharp conchoidal fracture edges and vibrant internal coloration often associated with glass manufacturing or rare natural volcanic rapid-cooling conditions.
Lore & History
Associated with the throat chakra in metaphysical practices, traditionally used for enhanced communication, emotional clarity, and calming energy, though these are entirely traditional beliefs without scientific backing.