Name/Title
ColemaniteEntry/Object ID
2009.62.224Description
Description: Common Name: Colemanite
Chemistry: CaB3O4(OH)3-H2O, Hydrated Calcium Borate Hydroxide
Group: Borates
Location: Billie Mine, Death Valley, CA
Description: Large white crystals, 1/2" to 6" in layered sections with a section of bunched smaller crystals.
PHYSICAL CHARACTERISTICS:
Color is white to clear.
Luster is vitreous.
Transparency crystals are transparent to translucent.
Crystal System is monoclinic; 2/m
Crystal Habits are quite variable, but include the short prismatic crystals always with complicated facets. Equant crystals that appear stubby and bead-like are also common. The crystals are sometimes flattened and can appear bladed. The terminations are either blunted or steeply pyramidal. Also massive, lamellar and granular habits are found.
Cleavage is perfect in one direction and distinct in another.
Fracture is uneven.
Hardness is 4.5
Specific Gravity is approximately 2.4 (somewhat lower than average)
Streak is white.
Associated Minerals are calcite, celestite, borax, ulexite, kernite, hydroboracite and other borate minerals.
Other Characteristics: exfoliates (peels off) upon heating.
Best Field Indicators are crystal habit, associations, locality, density, cleavage and hardness.Collection
RAGM Mineral CollectionAcquisition
Accession
2009.62Source or Donor
Museum Collection of MineralsAcquisition Method
DonationDimensions
Width
1-1/8 inDepth
6 inLength
18 inLocation
Date
August 28, 2022Location
Wall
NorthBuilding
Storage (old gift shop upstairs) North wall, I-6 frontCategory
PermanentMoved By
Rawley WyattDate
May 15, 2014Location
Container
CenterDrawer
Bottom tierShelf
West side, West sideWall
centerBuilding
Storage (old gift shop upstairs)Category
PermanentMoved By
Wendy MondryDate
January 6, 2010Location
Cabinet
I-6 frontWall
NorthBuilding
Storage (old gift shop upstairs)Category
Permanent
