Wulfenite

Object/Artifact

-

Crater Rock Museum

Name/Title

Wulfenite

Entry/Object ID

2004.1.13

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: Found at Erupeion Mine, Los Lamentos Mountains, Municipal de Ahumada, Chihuahua, Mexico Description: This is a fairly large specimen of wulfenite with beautifully cubic crystals colored a rusty brown almost a caramel in coloring. 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, Suomynona Collection

Acquisition

Accession

2004.1

Source or Donor

Suomynona Mineral Collection

Acquisition Method

Donation

Other Names and Numbers

Other Number

Other Number: 2004.1

Dimensions

Width

5-3/4 in

Depth

3-1/2 in

Length

7-3/4 in

Weight

6.71 oz

Dimension Notes

Dimension taken at widest points

Location

Location

* Untyped Location

RD-1

Category

Permanent

Moved By

Ian Cunningham

Date

August 28, 2022

Location

Container

right

Drawer

bottom tier

Shelf

north side, north side

Wall

center

Hallway

Discovery Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Wendy Mondry

Date

December 26, 2008

Location

Cabinet

I-6 rear

Wall

North

Building

Storage (old gift shop upstairs)

Category

Permanent