Jamesonite

Object/Artifact

-

Crater Rock Museum

Name/Title

Jamesonite

Entry/Object ID

2014.1.43

Description

Chemical Composition: Al(OH)3 Crystal System: Hexagonal System Description: Common Name: Jamesonite Chemistry: Pb4FeSb6S14 Group: Sulfides Location: Unknown Description: Dark gray rocky matrix with needle-like silver crystals. Physical Charateristics: 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. • Notable Occurrences include Tsumeb, Nambia; Congo; Morocco; Australia; Germany, Leadville, Colorado and Arizona, USA. • Best Field Indicators are its crystal habit (especially twins), heaviness, high refraction and luster. Hardness: 7 Quartz Rock Type: Sedimentary

Collection

RAGM Mineral Collection

Acquisition

Accession

2014.1

Source or Donor

Crater Rock Museum (unknown donors)

Acquisition Method

Gift

Dimensions

Height

2-3/8 in

Width

1-1/8 in

Length

2-1/4 in

Location

Location

Shelf

Bottom Row

Cabinet

Case# 20

Wall

West

Building

Freida Smith Hall

Category

Permanent