Jun 3 2014
Ilesite is named after the American metallurgist Malvern Wells Iles of Denver, Colorado, USA. He performed the first chemical analysis of this mineral.
Ilesite belongs to the Rozenite group, and was discovered in 1881.
Properties of Ilesite
The following are the key properties of ilesite:
- Cell Data
- Space group: P21/n (synthetic MnSO4 •4H2O)
- a = 5.94(1)
- b = 13.76(2)
- c = 8.01(1)
- β = 90°48(10)'
- Z = 4
- Crystal Data
- Monoclinic
- Point group: 2/m
- As prismatic crystals, to 1mm
- Commonly aggregated as vein fillings and incrustations
- X-ray powder pattern: (ICDD 32-651)
- 4.55 (100), 5.5 (90), 4.01 (90), 2.99 (90), 3.46 (80), 3.28 (80), 3.01 (70)
- Chemical Composition
| Elements |
Content |
| SO3 |
36.07 |
| H2O |
31.60 |
| MnO |
22.31 |
| ZnO |
5.97 |
| FeO |
4.18 |
| Total |
100.13 |
- Optical Properties
- Optical class: Biaxial (–)
- Orientation: Y = b; Z ^ c = 5°; α = 1.508; β= 1.518; γ = 1.522
- 2V (meas.) = Moderate
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.29 gm/cm3
note: Specific gravity of ilesite = 2.26 gm/cm3 |
| Photoelectric |
PEIlesite = 9.31 barns/electron
U = PEIlesite x ρElectron density = 21.33 barns/cm3 |
| Fermion index |
Fermion index = 0.0054171149
Boson index = 0.9945828851 |
Radioactivity
|
Ilesite is not radioactive
|
How to Identify Ilesite
Ilesite can be identified in the field by its green, greenish-white, and white variations. It is transparent, and is made of a number of single crystals that are non-fluorescent. It has crust-like aggregates on matrix, and is non-magnetic with a glassy lustre and white streak.
The density of ilesite is 2.261 g/cm3, with a hardness of 2 to 3 – between gypsum and calcite.
Global Distribution
Globally, ilesite can be found in the following locations:
- USA - from the McDonnell claim, Montezuma district, Hall Valley, Park Co. and at the Penn mine, Summit Co. Colorado
- Czech Republic - Chvaletice
- Japan - Jokoku mine, southwest Hokkaido
- Canada - Silver King mine, Galena Hill, Yukon Territory
Occurrence of Ilesite and Useful Mineral Association
Ilesite occurs as a rare secondary mineral in the oxidized zones of sulfide deposits.
It is often associated with minerals such as pyrite, rozenite, epsomite, sphalerite, galena, copiapite, chvaleticeite, gypsum, and melanterite.
References
http://www.mindat.org/min-2009.html
http://webmineral.com/data/Ilesite.shtml
http://rruff.geo.arizona.edu/doclib/hom/ilesite.pdf