Name/Title
BrochantiteEntry/Object ID
2004.1.91Description
Chemical Composition: Cu4SO4(OH)6
Crystal System: Monoclinic System
Description: Common Name: Brochantite
Group Name: Sulfates
Chemistry: Cu4SO4(OH)6
Location: Great Australia mine, Australia
Description: Green fuzzballs.
PHYSICAL CHARACTERISTICS:
Color is a bright emerald green or dark green to almost black.
Luster is vitreous to pearly on cleavage surfaces.
Transparency: Crystals are transparent to translucent.
Crystal System is monoclinic; 2/m.
Crystal Habits include acicular or fibrous crystals aggregated into coatings and tufts as well as small tabular crystals and reniform, massive or granular specimens. Terminations tend to be rounded or dome-like. Twinning is common and gives an orthorhombic look to larger crystals.
Cleavage is perfect in one direction nearly perpendicular to length.
Fracture is uneven.
Hardness is 3.5 - 4
Specific Gravity is approximately 3.9+ (above average for translucent minerals)
Streak is green.
Other Characteristics: Does not effervesce in hydrochloric acid.
Associated Minerals are limonite, cuprite, chrysocolla, cyanotrichite, malachite, langite, posnjakite and azurite. .
Best Field Indicators are crystal habit, associations, hardness, cleavage, non-reaction to hydrochloric acid and color
Fracture: uneven
Hardness: 3 Calcite
Luster: Vitreous
Occurrence: Formed in arid climates or in rapidly oxidizing copper
Notable Occurrences include numerous locations in Chile; Ural Mountains, Russia; England; Italy; Romania; Zaire and several locations in Arizona, Nevada, California, New Mexico and Utah, USA
Specific Gravity: 3.9
Streak: green
Variety: Brochantite is similar to other fibrous green copper minerals that form in oxidation zones such as the carbonate mineral malachite, the halide mineral atacamite and the closely related sulfate mineral antlerite. This brings up a number of identification problems. Acicular malachite will effervesce in warm hydrochloric acid and brochantite will not. Atacamite is slightly softer and is usually less transparent. Antlerite is all but indistinguishable by ordinary means although its terminations are typically flatter than the rounded terminations of brochantite.Collection
Suomynona Mineral CollectionAcquisition
Accession
2004.1Source or Donor
Suomynona Mineral CollectionAcquisition Method
DonationDimensions
Height
1-3/4 inWidth
1-1/2 inLength
2-1/2 inWeight
0.1 ozDimension Notes
Dimension taken at widest pointsLocation
Location
Drawer
BottomShelf
Center, CenterWall
EastHallway
Discovery HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Steve MillerDate
October 23, 2012Location
Drawer
CenterShelf
Top, TopWall
northHallway
Discovery HallBuilding
Crater Rock MuseumCategory
PermanentMoved By
Lehman R.Date
August 26, 2009Location
Cabinet
Case# 56Wall
CenterBuilding
Freida Smith HallCategory
Permanent
