Wulfenite

Object/Artifact

-

Crater Rock Museum

Name/Title

Wulfenite

Entry/Object ID

2014.1.117

Description

Assemblage Zone: oxidation zone Chemical Composition: PbMo4 Crystal System: Tetragonal System Description: Common Name: Wulfenite Chemistry: PbMoO4, Lead Molybdate Class: Sulfates Group Name: Tugstates Uses: A minor ore of molybdenum and as mineral specimens Location: Arizona Description: Two orange-ish brown, tabolar Wulfenite crystals on a bed of drusy calcite. Matrix is a dark red to pinkish material inter-woven with clear crystals. PHYSICAL CHARACTERISTICS: Color is red, orange, yellow, silver and white. Luster is vitreous. Transparency: Crystals are transparent to translucent. Crystal System is tetragonal; 4/m or 4 Crystal Habits include very thin square or octahedral pinacoidal plates with pyramidal faces truncating just the edges of the crystal. At times the pyramids become prominant and psuedo-dipyramidal crystal habits are seen, sometimes because of twinning. Prismatic faces are also seen and can make psuedo-cubic crystals. Also encrusting and cavernous aggregates due to intergrowth of crystal plates. Cleavage is perfect in one direction. Fracture is conchoidal. Hardness is 3. Specific Gravity is approximately 6.8 (very heavy for translucent minerals) Streak is white. Associated Minerals are mimetite, limonite, smithsonite, vanadinite and galena. Other Characteristics: index of refraction is 2.28-2.40 (very high, but typical of lead minerals). Best Field Indicators are crystal habit, color, density and luster. Fracture: Conchoidal Grain Size: Crystalline Hardness: 3 Calcite Luster: Glassy Occurrence: Wulfenite is found in many localities, associated with lead ores as a secondary mineral associated with the oxidized zone of lead deposits. It is also a secondary ore of molybdenum, and is sought by collectors. Occurs in the oxidation zone through out the world but the most notable occurances include Morocco; Tsumeb, Nambia; Mexico and Arizona and New Mexico, USA. Rock Color: Medium Rock Type: Sedimentary Specific Gravity: 6.8 Streak: White Texture: Crystalline Variety: It can be most often found as thin tabular crystals with a bright orange-red to yellow-orange color, sometimes brown, although the color can be highly variable. In its yellow form it is sometimes called "yellow lead ore". Wulfenite is not hard enough to be classified as a gemstone

Collection

Suomynona Mineral Collection, RAGM Mineral Collection

Acquisition

Accession

2014.1

Source or Donor

Crater Rock Museum (unknown donors)

Acquisition Method

Gift

Other Names and Numbers

Other Number

Other Number: 2004.1

Dimensions

Width

2-1/4 in

Depth

1-1/2 in

Length

2-1/2 in

Dimension Notes

Dimension taken at widest points

Location

Location

Cabinet

G-1 front

Wall

North

Building

Storage (old gift shop upstairs)

Category

Permanent