Name/Title
Hematite var. speculariteEntry/Object ID
2011.57.106(a)(b)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: Angular block with several sides, one thick band runs through specimen which is a dark magenta while the remaining areas are dark gray. Some metallic luster. (very small specks).
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 BrownCollection
Museum Collection of FossilsDimensions
Width
3-3/8 inDepth
2-7/8 inLength
4-3/8 inLocation
Location
Shelf
CS-H-7Room
Curation StorageBuilding
Crater Rock MuseumCategory
StorageMoved By
Jillian Mather KettleyDate
February 8, 2024
