Cerussite

Object/Artifact

-

Crater Rock Museum

Cerussite

Cerussite

Name/Title

Cerussite

Entry/Object ID

2009.62.84

Description

Chemical Composition: PbCO3 Crystal System: Orthorhombic System Description: Common Name: Cerussite Chemistry: PbCO3, Lead Carbonate Group: Carbonates Location: Pocos, South Africa Description: Small specimen with twinned crystals, translucent gray in color on a small gray course matrix. PHYSICAL CHARACTERISTICS: Color is usually colorless or white, also gray, yellow, and even blue-green. Luster is adamantine to almost submetallic and sometimes greasy. Transparency Crystals are transparent to translucent. Crystal System is orthorhombic; 2/m 2/m 2/m. Crystal Habits twinning is common and expected (see above), single crystals can be prismatic with blunted pyramidal terminations. Some specimens show acicular white crystals. Also, reniform, earthy, and crusty varieties are found. Cleavage is not as good as other carbonates, but still considered good in one direction. Fracture is conchoidal and brittle. Hardness is 3-3.5. Specific Gravity is 6.5+ (very dense for a generally transparent mineral). Streak is white or colorless. Other Characteristics: Refractive index of 2.07 (very high) and prismatic crystals are striated lengthwise. Associated Minerals are barite, calcite, anglesite, and other secondary minerals and especially galena. Best Field Indicators are its crystal habit (especially twins), heaviness, high refraction and luster. Fracture: conchoidal Hardness: 3 Calcite Luster: Vitreous Occurrence: Cerussite is found in the oxidation zone of lead deposits usually associated with galena. Rock Type: Sedimentary Specific Gravity: 6.5 Streak: white Variety: Cerussite is a minor ore of lead. It has a very high luster due mostly to the lead content. Just as leaded crystal glass sparkles more brilliantly because of its lead content, so too does cerussite. The lead raises the index of refraction of cerussite to just over 2.07. The lead is also responsible for its increased specific gravity. Cerussite has one of the highest densities for a transparent mineral. It is over six and a half times as dense as water. Most rocks and minerals average only around three times the density of water.

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Height

3/4 in

Width

1-1/2 in

Length

1-3/4 in

Weight

0.25 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

FS-9

Room

Frieda Smith Hall

Building

Crater Rock Museum

Date

August 5, 2023