Garnet (likely Almandine or Pyrope)
Almandine-Pyrope solid solution series species · Semi-Precious Gemstone / Mineral Specimen
Crystal System
Cubic (Isometric); typically forms as dodecahedrons or trapezohedrons, though this specimen appears as a fractured, weathered pebble or rough crystal.
Mineral Group
Silicates (Nesosilicates); Garnet group
Chemical Formula
Fe3Al2(SiO4)3 to Mg3Al2(SiO4)3
Formation Process
Metamorphic formation; typically forms under high pressure and temperature conditions during the regional metamorphism of argillaceous (clay-rich) sedimentary rocks.
About This Crystal
The specimen shows a deep reddish-brown to dark burgundy color. It appears mostly opaque with some translucent edges under bright light. The luster is vitreous to slightly resinous where the surface is fractured, and the texture is somewhat rugged and weathered.
Physical Characteristics
Color: Deep red-brown; Streak: White; Cleavage: None (indistinct parting only); Fracture: Sub-conchoidal to uneven; Specific Gravity: 3.6 - 4.3; Fluorescence: Usually inert.
Optical Properties
Singly refractive (Isotropic); Refractive Index: 1.76 - 1.83; No pleochroism due to cubic structure; high dispersion but masked by dark body color in rough form.
Hardness & Durability
Origin Region
Worldwide; notable sources include India, Sri Lanka, USA (Idaho/New York), and Madagascar. Found typically in metamorphic rocks like mica schists.
Hardness & Durability
Mohs Hardness: 6.5 - 7.5; Toughness: Fair to Good; Excellent wearability for jewelry but sensitive to rapid temperature changes.
Care & Maintenance
Clean with warm soapy water and a soft brush. Avoid ultrasonic cleaners if the stone contains significant inclusions. Store separately to prevent scratching softer stones or being scratched by harder ones like Sapphire.
Rarity & Value
Common (in rough form); Value is determined by transparency and 'color flash' when cut. Rough specimens of this size and opacity are generally low in monetary value but excellent for study.
Special Characteristics
Often contains needle-like inclusions of rutile; some varieties may show asterism (star effect) or color change under different light sources, though not apparent in this specific rough specimen.
Lore & History
Historically used in jewelry dating back to Ancient Egypt and Rome. Symbolically associated with the Root Chakra, it has traditionally been viewed as a stone of protection, strength, and vitality across many cultures.