Galena
Galena (Lead Sulfide) · Mineral Specimen / Industrial Ore
Crystal System
Cubic (Isometric); habit is typically cubic, octahedral, or massive granular as seen in this specimen.
Mineral Group
Sulfides (Galena Group)
Chemical Formula
PbS with trace silver (Ag), antimony (Sb), or zinc (Zn)
Formation Process
Hydrothermal; formed in medium to low-temperature hydrothermal veins and through metasomatic replacement in limestone or dolostone.
About This Crystal
The specimen shows an opaque, metallic luster with a lead-gray to bluish-gray color. It appears as embedded metallic grains within a darker, oxidized host rock (matrix).
Physical Characteristics
Color: Lead-gray; Streak: Lead-gray to black; Cleavage: Perfect cubic in three directions at 90 degrees; Fracture: Subconchoidal or uneven; SG: 7.2–7.6 (very heavy); Non-fluorescent.
Optical Properties
Opaque; metallic luster; isotropic (singly refractive); high reflectivity common for sulfide minerals.
Hardness & Durability
Origin Region
Common worldwide; notable deposits include Missouri (USA), Mexico, Peru, and Morocco. Found in hydrothermal veins and sedimentary environments.
Hardness & Durability
Mohs hardness: 2.5–2.75. Very soft and brittle; easily scratched by a copper coin. High density but low mechanical toughness.
Care & Maintenance
Wash hands after handling due to lead content. Clean with dry cloth or soft brush; avoid acids. Store in a dry environment to prevent oxidation (dulling) of the metallic luster.
Rarity & Value
Common; primary ore of lead. Value for specimens depends on crystal size and sharpness; industrial value is based on lead/silver yield.
Special Characteristics
Characteristic cubic cleavage fragments; exceptionally high density (heaviness) for its size; often Argentiferous (contains silver).
Lore & History
Used since ancient times (Ancient Egypt, Rome) as a lead ore and for cosmetics (kohl). In traditional lore, it is considered a grounding stone associated with the Root Chakra, believed to provide stability.