Galena in Quartz Matrix
Lead Sulfide with Silicon Dioxide · Mineral Specimen and Metallic Ore
Crystal System
Galena: Cubic (Isometric) system, often found in cubic or octahedral habits. Quartz: Trigonal system, hexangular prismatic habit.
Mineral Group
Sulfides (Galena) and Silicates (Quartz - Tectosilicate)
Chemical Formula
PbS (Galena) + SiO2 (Quartz)
Formation Process
Hydrothermal deposition in low to medium temperature veins, often replacing limestone or forming in volcanic rock cavities.
About This Crystal
Massive, grainy metallic grey galena embedded within a white to translucent crystalline quartz matrix. The galena shows a dull to sub-metallic luster, while quartz appears vitreous.
Physical Characteristics
Color: Lead-grey (Galena), White/Clear (Quartz). Streak: Lead-grey. Fracture: Subconchoidal. Galena is very dense (S.G. 7.4-7.6) and brittle.
Optical Properties
Opaque (Galena) to Transparent/Translucent (Quartz). Galena is isotropic with metallic luster; Quartz is uniaxial positive with low birefringence.
Hardness & Durability
Origin Region
Notable sources include Joplin region (Missouri), Tri-State district (USA), Bulgaria, and Naica (Mexico). Forms in hydrothermal veins.
Hardness & Durability
Galena: Mohs 2.5 (very soft). Quartz: Mohs 7.0 (hard). The specimen is fragile due to the soft galena and the brittle nature of quartz.
Care & Maintenance
Wash hands after handling (lead content). Clean with a soft dry brush; avoid ultrasonic cleaning or harsh chemicals. Keep away from children and pets.
Rarity & Value
Common mineral specimen. Value depends on the perfection of the crystals and the contrast between the lead ore and the matrix.
Special Characteristics
Galena exhibits high density and perfect cubic cleavage. Quartz may show triangular growth faces or phantom inclusions where minerals intergrow.
Lore & History
Historically the primary ore of lead. Ancient Egyptians used ground galena as kohl (eyeliner). In lore, it is believed to be a grounding stone that provides stability.