Hematite var. specularite

Object/Artifact

-

Crater Rock Museum

Name/Title

Hematite var. specularite

Entry/Object ID

2011.57.107

Description

Chemical Composition: Fe2O3 Crystal System: Hexagonal System Description: Common Name: Hematite var. specularite Chemistry: Fe2O3, Class: Oxides and Hydroxides Location: Negaunee Iron Formation, Empire Mine, Ishpeming, MI Description: Blocky, angular with one side showing agatized banding while encrusted with metallic ore (solid) present. The remainder has a speckled metallic luster. Gray to light pink (in a band). Physical Characteristics: •Color is steel or silver gray to black in some forms and red to brown in earthy forms. Sometimes tarnished with iridescent colors when in a hydrated form (called Turgite). •Luster is metallic or dull in earthy and oolitic forms. •Transparency: Crystals are opaque. •Crystal System is trigonal; bar 3 2/m •Crystal Habits include tabular crystals of varying thickness sometimes twinned, micaceous (specular), botryoidal and massive. also earthy or oolitic. •Cleavage is absent. However, there is a parting on two planes. •Fracture is uneven. •Hardness is 5 - 6 •Specific Gravity is 5.3 (slightly above average for metallic minerals) •Streak is blood red to brownish red for earthy forms. •Associated Minerals include jasper (a variety of quartz) in banded iron formations (BIF or Tiger Iron), dipyramidal quartz, rutile, and pyrite among others. •Notable Occurrences especially nice specimens come from England, Mexico, Brazil, Australia and the Lake Superior region. •Best Field Indicators are crystal habit, streak and hardness. Fracture: Uneven Grain Size: Medium Hardness: 6 Orthoclase Luster: Metallic Rock Origin: Terrestrial Rock Type: Sedimentary Specific Gravity: 5.3 Streak: Blood Red to Brown

Collection

Museum Collection of Fossils

Acquisition

Accession

2011.57

Source or Donor

Museum Collection of Fossils

Acquisition Method

Long-term Loan

Dimensions

Width

3 in

Depth

3-11/16 in

Length

3-1/4 in

Location

Location

Container

Center

Drawer

Front Row / 2nd Shel

Shelf

Left

Cabinet

Case # 51

Wall

North

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent