clinohumite
Sign in to saveClinohumite is an uncommon member of the humite group, a magnesium silicate according to the chemical formula (Mg, Fe)9(SiO4)4(F,OH)2. The formula can be thought of as four olivine (Mg2SiO4), plus one brucite (Mg(OH)2). Indeed, the mineral is essentially a hydrated olivine and occurs in altered ultramafic rocks and carbonatites. Most commonly found as tiny indistinct grains, large euhedral clinohumite crystals are sought by collectors and occasionally fashioned into bright, yellow-orange gemstones. Only two sources of gem-quality material are known: the Pamir Mountains of Tajikistan, and the T
Key facts
- Mineral.name
- Clinohumite
- Mineral.image
- File:Clinohumite.jpg
- Mineral.category
- Nesosilicate
- Mineral.formula
- (Mg,Fe)9(SiO4)4(F,OH)2
- Mineral.IMAsymbol
- Chu
- Mineral.system
- Monoclinic
- Mineral.class
- Prismatic (2/m) (same H-M symbol)
- Mineral.symmetry
- P21/c
- Mineral.unit cell
- a = 13.71 Å, b = 4.75 Å, c = 10.29 Å; β = 100.83°; Z = 2
- Mineral.color
- Brownish to orange, yellow, red
- Mineral.habit
- Granular, prismatic, twinned
- Mineral.twinning
- Simple, lamellar common on {100}
- Mineral.cleavage
- Poor on {100}
- Mineral.fracture
- Subconchoidal to uneven
- Mineral.mohs
- 6
- Mineral.luster
- Vitreous to resinous
- Mineral.refractive
- nα = 1.623 – 1.702 nβ = 1.636 – 1.709 nγ = 1.651 – 1.728
- Mineral.opticalprop
- biaxial (+)
via Wikipedia infobox
Wikidata facts
- Named after
- humite
- Image
- Clinohumite-d06-48b.jpg
Show 10 more facts
- Nickel-Strunz '10th ed', review of (9th ed/ 2009 update)
- 9.AF.55
- Commons category
- Clinohumite
- Nickel-Strunz 9th edition (updated 2009)
- 9.AF.55
- type locality (geology)
- Mount Somma
- crystal system
- monoclinic crystal system
- streak color
- white
- Mohs' hardness
- 6
- IMA Mineral Symbol
- Chu
- chemical formula
- Mg₉(SiO₄)₄F₂
- Strunz 8th edition (series ID, updated)
- VIII/A’.04
Sources (2)
via Wikidata · CC0
~8 min read
Encyclopedic overview
5 sectionsContents
- Properties
- Formation and occurrence
- Crystal structure
- See also
- References
{{Infobox mineral | name = Clinohumite | image = File:Clinohumite.jpg | category = Nesosilicate | formula = (Mg,Fe)9(SiO4)4(F,OH)2 | IMAsymbol=Chu | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = P21/c | unit cell = a = 13.71 Å, b = 4.75 Å, c = 10.29 Å; β = 100.83°; Z = 2 | color = Brownish to orange, yellow, red | habit = Granular, prismatic, twinned | twinning = Simple, lamellar common on {100} | cleavage = Poor on {100} | fracture = Subconchoidal to uneven | mohs = 6 | luster = Vitreous to resinous | refractive = nα = 1.623 – 1.702 nβ = 1.636 – 1.709 nγ = 1.651 – 1.728 | opticalprop = biaxial (+) | birefringence = +0.028 | 2V = Measured: 52° to 90° | pleochroism = X = golden yellow, yellow-brown, deep reddish yellow; Y = pale yellow, yellow-orange, light yellow; Z = pale yellow, yellow-orange, colorless | streak = White | gravity = 3.17–3.35 | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to translucent | other = | var1 = Titanclinohumite | var1text = Titanoan; (Mg,Fe2+,Ti)9 [(F,OH,O)2|(SiO4)4]
| references = }}
Excerpted from Wikipedia’s “clinohumite” article, available under the CC BY-SA 4.0 licence.