Garnet (var. Almandine)
Almandine Garnet (IMA approved) · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Cubic (Isometric); typically dodecahedral or trapezohedral habits
Mineral Group
Silicates; Nesosilicate group
Chemical Formula
Fe3Al2(SiO4)3 (frequently contains traces of Mg, Mn)
Formation Process
Metamorphic; forms under high pressure and temperature in regional metamorphic belts (schist and gneiss rocks).
About This Crystal
Deep brownish-red to purplish-red color with a vitreous to resinous luster. This specimen appears as an embedded rough crystal with an opaque to translucent body, showing characteristic dark, saturated tones with granular surface texture.
Physical Characteristics
Color: Deep red-brown; Streak: White; Cleavage: None; Fracture: Conchoidal to uneven; Specific Gravity: 4.1-4.3; Non-fluorescent.
Optical Properties
Refractive Index: 1.77-1.83; Singly refractive; No pleochroism; Often shows high dispersion (fire) in faceted stones; opaque in thick mass.
Hardness & Durability
Origin Region
Madagascar, India, Brazil, and USA (Idaho/New York); typically found in metamorphic schists and gneisses.
Hardness & Durability
Mohs Hardness: 7.5 to 8.0; Toughness: Good; Highly stable and durable for all types of jewelry.
Care & Maintenance
Clean with warm soapy water and a soft brush; safe for ultrasonic cleaning unless inclusions are significant; avoid sudden temperature changes.
Rarity & Value
Common mineral; value determined by color saturation and transparency. Mass-produced specimens are low cost, while gem-grade crystals are moderately priced.
Special Characteristics
Occasionally exhibits asterism (4-rayed or 6-rayed stars) due to rutile inclusions; magnetic due to high iron content.
Lore & History
Used since the Bronze Age as gemstones and abrasives; historically known as 'Carbuncle'. Traditionally associated with the Root Chakra, representing strength, security, and vitality.