Galena
Image: James Petts from London, England (CC BY-SA 2.0)
Mineral NameGalena
Chemical FormulaPbS
Mohs Hardness2.5
Crystal Systemcubic
Lustermetallic
Streak Colorlead gray
Cleavageperfect cubic (three directions at 90 degrees)
Fracturesubconchoidal to uneven
Specific Gravity7.4
Colorslead-gray, silvery-gray
Transparencyopaque
Type LocalityWorldwide, common in many lead-zinc deposits (e.g., Missouri, USA; Freiberg, Germany)
Mineral GroupSulfides
Usesprimary ore of lead, source of silver, collector specimens
Associated Mineralssphalerite, pyrite, chalcopyrite, quartz, calcite, fluorite, barite
Raritycommon
Description
This specimen displays a dark lead-gray color with a prominent metallic luster, characteristic of galena. Some areas show a more massive texture, while others exhibit the mineral's typical cubic cleavage.
Geological Context
Galena commonly forms in hydrothermal veins, often associated with other sulfide minerals, and can also occur in sedimentary rocks as replacements or disseminations. It is a key ore mineral in many types of lead-zinc deposits.
