Galena
Galena (Lead Sulfide) · Mineral Specimen and Opaque Ore Mineral; important as the primary ore of lead.
Crystal System
Cubic (Isometric); crystals are often cubes or octahedrons, but this specimen shows a massive, granular habit with stepped cleavage planes.
Mineral Group
Sulfides; Galena group.
Chemical Formula
PbS (Lead Sulfide), often containing silver (Ag), zinc (Zn), or antimony (Sb) inclusions.
Formation Process
Hydrothermal; forms in medium-temperature hydrothermal veins and as a replacement mineral in carbonate rocks like limestone or dolostone.
About This Crystal
An opaque, lead-gray mineral with a distinctive bright metallic luster on fresh surfaces. The specimen shows a granular, crystalline texture with small, shimmery facets that catch the light, indicating perfect cubic cleavage. The surface appears somewhat weathered or tarnished in darker areas.
Physical Characteristics
Color: Lead-gray to silvery; Streak: Lead-gray; Cleavage: Perfect cubic in three directions at 90 degrees; Fracture: Subconchoidal or uneven; Specific Gravity: 7.2–7.6 (very heavy); Tenacity: Brittle; Fluorescence: Generally none.
Optical Properties
Opaque; Metallic luster. High reflectivity on cleavage surfaces. Exhibits no pleochroism or birefringence as it is isotropic (cubic).
Hardness & Durability
Origin Region
Found worldwide in hydrothermal veins and sedimentary deposits; notable sources include Joplin (Missouri, USA), Mexico, Moravia (Czech Republic), and Cornwall (England).
Hardness & Durability
Mohs Hardness: 2.5 to 2.75. It is soft enough to be scratched by a copper coin. Its high brittle quality and low hardness make it unsuitable for wearable jewelry.
Care & Maintenance
Clean only with a soft, dry brush or brief rinse in distilled water. Avoid ultrasonic cleaners and harsh chemicals. Store in a stable environment; may tarnish (oxidize) over time. Important: Contains lead; wash hands after handling and avoid inhaling dust.
Rarity & Value
Common; very affordable as a mineral specimen. Value increases for large, well-formed cubic crystals or 'argentiferous' (silver-bearing) varieties.
Special Characteristics
High density (feels unexpectedly heavy for its size); perfect cubic cleavage allows it to break into smaller cubes. It can act as a semiconductor (historically used in early crystal radio sets).
Lore & History
Historically used since ancient Egypt for kohl (eye makeup) and as a major source of lead and silver throughout the Roman Empire. In traditional lore, it is considered a 'grounding' stone associated with the Root Chakra and is believed to promote strength and centering.