mineral
Galena (likely argentiferous galena)
Galena, PbS; commonly cubic or massive lead sulfide, sometimes containing silver
AI-generated identification · may be incorrectMetallic lead-gray to silvery color, bright metallic luster, opaque, very high density (specific gravity about 7.4–7.6), and perfect cubic cleavage; Mohs hardness 2.5–2.75. The specimen appears massive and fractured rather than showing clear cubes.
Identified More mineral →
Explore Galena (likely argentiferous galena) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Metallic lead-gray to silvery color, bright metallic luster, opaque, very high density (specific gravity about 7.4–7.6), and perfect cubic cleavage; Mohs hardness 2.5–2.75. The specimen appears massive and fractured rather than showing clear cubes.
Formation & geological history
Forms mainly in hydrothermal sulfide veins and carbonate-replacement deposits when lead- and sulfur-rich fluids precipitate in fractures, commonly with sphalerite, pyrite, and quartz. Most deposits range from Paleozoic to Cenozoic age.
Uses & applications
Primary ore of lead and an important historical source of silver; lead is used in batteries, radiation shielding, alloys, and ammunition. Specimens are collected for their metallic appearance and density.
Geological facts
Galena’s cubic cleavage is distinctive: broken pieces often produce stepped, right-angled surfaces. It can tarnish to dull gray or iridescent coatings and should not be handled around food because lead-bearing dust is toxic.
Field identification & locations
Identify it by unusually heavy weight, metallic gray color, softness, and cubic cleavage; a streak test gives a gray-black streak. Common localities include Missouri, Illinois, Idaho, Colorado, Peru, Mexico, and Australia.
