May 13 2014
Celsian is an uncommon feldspar mineral, which was first discovered in 1895 in Imfeld Binnental, Switzerland. The mineral was named after the Swedish astronomer and natural scientist, A.Celsius.
Properties of Celsian
The following are the key properties of Celsian:
- Cell Data
- Space Group: I2/c
- a = 8.622(4)
- b = 13.078(6)
- c = 14.411(8)
- β = 115:09(2)°
- Z = 8
- Crystal Data
- Monoclinic
- Point Group: 2/m
- As short prismatic to acicular crystals, with large prism faces, to 2cm; commonly massive. Twinning: Simple twins according to the Manebach, Baveno, or Carlsbad laws
- X-ray Powder Pattern: 3.47 (100), 3.35 (100), 3.02 (95), 2.582 (75), 3.26 (60), 3.80 (55), 6.52 (50)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| BaO |
39.72 |
39.92 |
40.84 |
| SiO2 |
32.43 |
31.07 |
32 |
| Al2O3 |
26.55 |
28.35 |
27.16 |
| F |
0.64 |
- |
- |
| H2O |
0.64 |
- |
- |
| CaO |
0.23 |
- |
- |
| Na2O |
0.16 |
- |
- |
| Fe2O3 |
0.12 |
0.36 |
- |
| MgO |
0.11 |
- |
- |
| Total |
100.82 |
99.94 |
100 |
- Optical Properties
- Optical Class: Biaxial (+)
- Orientation: Y = b; X ^ c = 3°-5°; Z ^ a = 28°-30°
- α = 1.579-1.587
- β = 1.583-1.593
- γ = 1.588-1.600
- 2V(meas.) = 83°-92°
- Estimated Properties
| Electron density |
Bulk density (electron density)=3.15 g/cm3
note: Specific gravity of Celsian =3.4 g/cm3 |
| Photoelectric |
PECelsian = 159.23 barns/electron
U= PECelsian x ρElectron density= 501.79 barns/cm3 |
| Fermion index |
Fermion index = 0.07
Boson index = 0.93 |
Radioactivity
|
Celsian is not radioactive
|
How to Identify Celsian
Celsian is either colorless, or occurs in yellow or white. It has perfect cleavage, transparent appearance, and non-fluorescent luminescence. It exhibits brittle fractures, white streak and vitreous luster. The mineral can appear as well-formed granular crystals.
The average density of celsian is 3.25 g/cm3, and its hardness ranges from 6 to 6.5.
Global Distribution
Celsian is distributed in the following places:
- Jakobsberg and Langban, VÄarmland, Sweden
- Simplon region, Valais, Switzerland
- Franklin, Sussex Co. New Jersey, USA
- Big Creek, Fresno Co. and Trumbull Peak, near Incline, Mariposa Co. California
- Benallt mine, Rhiw, Lleyn Peninsula, Wales
- Aberfeldy, Scotland
- Burultas deposit, west of Lake Balkhash, Kazakhstan
- Otjosondu, Namibia
- Piggery Creek, Broken Hill, New South Wales, Australia
- Kaso mine, Totiki Prefecture, Japan
Occurrence of Celsian and Useful Mineral Association
Celsian occurs in amphibolite-grade, regional, or contact metamorphic, Mn, Ba-rich rocks.
It is closely associated with muscovite, dolomite, spessartine, zoisite, quartz, taramellite, cymrite, barite, hyalophane, rutile, rhodonite, rhodochrosite, hausmannite, jacobsite, paracelsian, manganoan biotite, and manganoan aegirine.
References