Galena

Object/Artifact

-

Crater Rock Museum

Galena

Galena

Name/Title

Galena

Entry/Object ID

2009.62.6

Description

Chemical Composition: PbS Crystal System: Cubic or Isometric S Description: Common Name: Galena Chemistry: PbS lead Sulfide Group: Sulfides Location: Missouri Description: Shinny, Almost rectangular looks a lot of very thin layers packed together the sides almost look like puzze pieces. PHYSICAL CHARACTERISTICS: Color is lead to silver gray sometimes with a bluish tint. Luster is metallic to dull in weathered faces. Transparency crystals are opaque. Crystal System is isometric; 4/m bar 3 2/m Crystal Habits include the cube, octahedron and combinations of the two. Spinel twinning is possible forming flattened crystals. Also massive and granular. Cleavage is perfect in four direction forming cubes. Fracture is uneven and rarely seen because of the perfect cleavage. Hardness is 2.5+ Specific Gravity is approximately 7.5+ (heavy even for metallic minerals) Streak is lead gray Associated Minerals are calcite, dolomite, sphalerite, pyrite and other sulfide minerals, also lead oxidation minerals such as cerussite and anglesite. Other Characteristics: brighter metallic luster on cleavage surfaces than on crystal faces. Best Field Indicators are crystal habit, cleavage and, perhaps most importantly, density. Fracture: uneven Hardness: 2 Gypsum Luster: Metallic Occurrence: Lead sulfide ore veins, and disseminated in igneous and sedimentary rocks. Rock Type: Sedimentary Specific Gravity: 7.5 Streak: lead gray Texture: Microcrystaline Variety: Its characteristic cubes, distinctive cleavage and high density make it easy to identify and a favorite in high school geology labs. The structure of Galena is identical to that of halite, NaCl. The two minerals have the same crystal shapes, symmetry and cleavage. Some Galena may contain up to 1% silver in place of lead. The large volume of Galena that is processed for lead produces enough Silver as a by product to make Galena the leading ore of Silver.

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Width

2 in

Depth

2-3/4 in

Length

3-1/2 in

Weight

4.06 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

FS-9

Room

Frieda Smith Hall

Building

Crater Rock Museum

Category

Permanent