May 13 2014
Butlerite was named after Professor Gurdon Montague Butler (1881–1961), an American mining geologist associated with the University of Arizona in Tucson, Arizona, USA.
Properties of Butlerite
The following are the key properties of butlerite:
- Cell Data
- Space group: P21/m
- a = 6.44–6.50
- b = 7.31–7.37
- c = 5.84–5.87
- β = 108°23(5)’ - 108°28(20)’
- Z = 2
- Crystal Data
- Monoclinic
- Point group: 2/m
- Tabular on {001} or {100}, may be pseudo-octahedral
- Twinning: On {101}, very common
- X-ray powder pattern: 4.97 (FF), 3.15 (F), 3.59 (mF), 3.05 (mF), 3.22 (mf), 2.48 (mf), 6.17 (ff)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
| SO3 |
38.63 |
39.07 |
| Fe2O3 |
36.31 |
38.96 |
| H2O |
22.83 |
21.97 |
| Na2O |
2.73 |
- |
| Al2O3 |
0.55 |
| FeO |
0.41 |
- |
| Total |
101.46 |
100.00 |
- Optical Properties
- Optical class: Biaxial (-)
- Pleochroism: X = colorless; Y = very pale yellow; Z = pale yellow
- Orientation: Z = b; X ^ c = –18°
- α = 1.593–1.604; β = 1.665–1.674; γ = 1.731–1.741
- 2V(meas.) = Large
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.56 g/cm3
note: Specific gravity of butlerite =2.55 g/cm3 |
| Photoelectric |
PEButlerite = 8.92 barns/electron
U=PEButlerite x ρ electron density= 22.85 barns/cm3 |
| Fermion index |
Fermion index = 0.0072162779
Boson index = 0.9927837221 |
Radioactivity
|
Butlerite is not radioactive
|
How to Identify Butlerite
Butlerite can be identified in the field by its color variations, such as dark yellow and orange. Its transparent form has {100} perfect cleavage. This mineral has a vitreous luster with light yellow streak. It is non-fluorescent.
The density of butlerite is 2.55 g/cm3 with a hardness of 2.5 – approximate to a finger nail.
Global Distribution
Butlerite is distributed in the following places:
- USA - From the United Verde copper mine, Jerome, Yavapai Co. Arizona; at the Lone Star mine, La Bajada district, Santa Fe Co. New Mexico; in the Dexter No. 7 mine, Calf Mesa, San Rafael district, Emery Co. Utah; from near Cimarron, Gunnison Co. Colorado
- Argentina - At the Santa Elena mine, Quebrada de La Alcaparrosa, San Juan Province
- Chile - From Chuquicamata and Quetena, west of Calama, Antofagasta
- Iran - At Saghand, Yazd
- China - From the Xitieshan Pb–Zn mine, south of Mt. Qilianshan, Chaidamu, Qinghai Province
Occurrence of Butlerite and Useful Mineral Association
Butlerite is rarely formed from the oxidation of pyritic ore; it may be formed under fumarolic conditions from mine fires.
It is often associated with minerals such as parabutlerite, fibroferrite, copiapite, and other iron sulfates.
References