May 12 2014
Brucite is the mineral form of magnesium hydroxide, first discovered in 1824 from the New Jersey serpentine, USA. The mineral was named after the American mineralogist, A. Bruce.
Properties of Brucite
The following are the key properties of Brucite:
- Cell Data
- Space Group: P3m1
- a = 3.142(1)
- c = 4.766(2)
- Z = 1
- Crystal Data
- Hexagonal
- Point Group: 3 2/m
- Crystals tabular {0001}, to 19cm, in platy or foliated masses and rosettes; also fibrous, to 50cm; granular, massive
- X-ray Powder Pattern: 2.365 (100), 4.77 (90), 1.794 (55), 1.573 (35), 1.494 (18), 1.373 (16), 1.310 (12)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| MgO |
68.29 |
60.33 |
69.11 |
| H2O |
30.74 |
28.6 |
30.89 |
| MnO |
0.84 |
- |
- |
| Fe2O3 |
0.1 |
1.95 |
- |
| FeO |
- |
9.57 |
- |
| Total |
99.97 |
100.45 |
100 |
- Optical Properties
- Optical Class: Uniaxial (+); anomalously biaxial
- ω = 1.56–1.59
- ε = 1.58–1.60
- 2V(meas.) = Small
- Estimated Properties
| Electron density |
Bulk density (electron density)= 2.44 g/cm3
note: Specific gravity of Brucite = 2.37 g/cm3 |
| Photoelectric |
PEBrucite = 1.01 barns/electron
U= PEBrucite x ρ Electron density= 2.45 barns/cm3 |
| Fermion index |
Fermion index = 0.04
Boson index = 0.96 |
Radioactivity
|
Brucite is not radioactive
|
How to Identify Brucite
Brucite occurs in a white, yellow, gray-blue, gray or blue color. It exhibits perfect cleavage, transparent appearance, non-fluorescent luminescence, and non-magnetic properties. The mineral has irregular fractures, vitreous luster and white streak.
It can be formed as lamellar structures or fibrous crystals. The average density of the mineral is 2.39 g/cm3, and its hardness ranges from 2.5 to 3.
Global Distribution
Brucite is distributed in the following places:
- Hoboken, Hudson Co. New Jersey
- Wood’s Chrome mine, near Texas
- Lancaster Co. Pennsylvania
- Tilly Foster mine, Brewster, Putnam Co. New York
- Near Gabbs, Gabbs district, Nye Co. Nevada
- Crestmore quarry, Riverside Co. California
- Asbestos and Wakefield, Quebec, Canada
- Mt. Vesuvius, Campania, and at Teulada, Sardinia, Italy
- Unst, Shetland Islands, and at Camas Mor, Isle of Muck, Scotland
- Langban and Nordmark, Varmland, Sweden
- Asbest, Ural Mountains, Russia
- Ethyl mine, Mutorashanga, Zimbabwe
- Phalaborwa, Transvaal, South Africa
Occurrence of Brucite and Useful Mineral Association
Brucite occurs as a common alteration of periclase in marble, and a low-temperature hydrothermal vein mineral in metamorphic limestones and chlorite schists. It is closely associated with chrysotile, talc, artinite, hydromagnesite, magnesite, dolomite, aragonite, and calcite.
References