Carmichaelite is a rare titanium chromium iron hydroxide, typically cinnamon brown to black. It occurs as microscopic inclusions in mantle-derived pyrope crystals carried up in kimberlite.
Is this carmichaelite?
4-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch carmichaelite with a known reference. Carmichaelite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: greasy, shining.
- 3Match the color rangeCompare against the expected color range: cinnamon brown, black.
- 4Look at form & habitCrystal system: orthorhombic. Typical habit: inclusions, microscopic crystals.
Often confused with
Carmichaelite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Rutile is the harder of the two (Mohs 6-6.5 vs. 2.5); luster reads greasy, shining on Carmichaelite and adamantine to submetallic on Rutile.
How to tell apart: Ilmenite is the harder of the two (Mohs 5-6 vs. 2.5); luster reads greasy, shining on Carmichaelite and metallic to submetallic on Ilmenite.
Often found alongside carmichaelite
Minerals reported to co-occur with carmichaelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ti,Cr,Fe)(O,OH)₂
- Mohs hardness
- 2.5
- Density
- 1.602 g/cm³
- Colors
- Cinnamon brownBlack
- Luster
- Greasy, shining
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Inclusions, microscopic crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Thought to form in saline marine deposits by reaction of pre-existing saline minerals with fluids high in potash
Where rockhounds find carmichaelite
Classic worldwide localities
- New Mexico, in the Carlsbad potash district, Eddy Co., and adjacent parts, Texas, USA
- Paradox basin, Grand Co., Utah, USA
- Leopoldshall and Westeregeln, near Stassfurt, Magdeburg district, Germany
- Kalusz, Ukraine
- Maman, Azerbaijan
- Barcelona and Lerida Provinces, Spain
Field-hunting tip
Where it forms: Thought to form in saline marine deposits by reaction of pre-existing saline minerals with fluids high in potash. If you start seeing kieserite, sylvite, halite in float, you are in the right ground. Typical habit: inclusions, microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify carmichaelite?+
Where is carmichaelite found?+
What rocks look like carmichaelite?+
What minerals are found with carmichaelite?+
What kind of rock does carmichaelite form in?+
What is carmichaelite used for?+
Find carmichaelite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
