Name/Title
RhodochrositeEntry/Object ID
2014.1.53Description
Chemical Composition: Al(OH)3
Crystal System: Hexagonal System
Description: Common Name: Rhodochrosite
Chemistry: MnCO3
Group: Carbonates
Location: Sweet Home Mine, Alma, Colorado
Description: Small specimen with very irregular surface covered in pinkish crystals.
Physical Charateristics:
•Color is red to pink, sometimes almost white, yellow and brown.
• Luster is vitreous to resinous.
• Transparency: Crystals are transparent to translucent.
• Crystal System is trigonal; bar 3 2/m.
• Crystal Habits include the rhombohedrons and scalahedrons with rounded or curved faces that can obscure the crystal shape. Some crystals can be flattened to a bladed habit and these are sometimes aggregated into rosettes or minute crystals into spherules. Also botryoidal, globular, stalactitic, layered, nodular, vein-filling and granular. Twinning is somewhat common forming penetration twins and contact twins similar to calcite's twins.
• Cleavage is perfect in three directions forming rhombohedrons.
• Fracture is uneven.
• Hardness is 3.5 - 4.
• Specific Gravity is approximately 3.5 (above average)
• Streak is white.
• Other Characteristics: Pink and white banding in massive forms, non-fluorescence and specimens effervesce easily with dilute acids.
• Associated Minerals include calcite, ankerite, alabandite, rhodonite, bementite, spessartine, fluorite, manganite, quartz and many metal sulfides.
• Notable Occurrences are numerous and include the famous Sweet Home Mine, Alma, Park County and American Tunnel, Silverton, Colorado; Butte, Montana; the mines of Franklin, New Jersey; Humboldt Mine, Cochise County, Arizona and many sites in California, USA. Also found in Catamarca, Argentine; Huaron Mine and several mines in Ancash Department, Peru; Kara oba, Kazakhatan; Sacrimb, Transylvania, Romania; Cornwall, England; Harz Mountains, Germany; Tsumeb, Otavi, Namibia; Santa Eulalia and Magdalena, Mexico; N'Chwanging Mine, Hotazel, South Africa; Mont Saint-Hilaire, Quebec, Canada and many other localities from around the world.
• Best Field Indicators are color, crystal habit, reaction to acid, non-fluorescence and perfect cleavage.
- See more at: http://www.galleries.com/Rhodochrosite#sthash.LzVsM8u8.dpuf
Hardness: 7 Quartz
Rock Type: SedimentaryCollection
RAGM Mineral CollectionAcquisition
Accession
2014.1Source or Donor
Crater Rock Museum (unknown donors)Acquisition Method
GiftDimensions
Height
3 inWidth
1-1/8 inLength
2 inLocation
Location
Display Case
FS-11Room
Frieda Smith HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Ian CunninghamDate
December 27, 2023