Breunnerite
| Breunnerite | |
|---|---|
| File:Breunnerite detail.jpg Breunnerite from Bolzano. Italy | |
| General | |
| Category | Carbonate mineral |
| Formula | (Mg, Fe) CO 3 |
| Crystal system | Trigonal[1] |
| Identification | |
| Color | from yellowish or gray-brown to brown |
| Cleavage | perfect on a rhombohedron |
| Mohs scale hardness | 4.0-4.5 |
| Luster | metallic |
| Diaphaneity | translucent to opaque |
| Density | 3.0-3.2 (calculated) |
Breunnerite, also known as brown spar[2]: 258 (German: braunspat) is a variety of magnesite, with a magnesium/iron ratio of 90/10 to 70/30.[1]
Name and history
[edit | edit source]It has been described by Wilhelm Karl Ritter von Haidinger in samples of Pfitsch pass, Zamsergrund and Großer Mt Greiner, Zemmgrund, two cities of the Ziller Valley, Tyrol, Austria.[3]
Haidinger named the new variety of the magnesite in honor of Count August Breunner[4] (sometimes the family name is written as Breuner; 1796-1877), a famous collector of minerals and fossils, as well as a high-ranking government official of Austria-Hungary.[1]
In 19th century mineralogy, as well as in mining and among geologists, breunnerite and its close analogues from the isomorphic series magnesite → siderite were more often known under the capacious morphological name ″brown spar″.[5]: 34
Application
[edit | edit source]Breunerite is widely used in firing during the formation of raw materials for the subsequent production of refractories. When magnesium carbonate, which is part of breunerite, is brought to a temperature of about 600°C, it enters the firing process as a mineralizer, first decomposing and then reacting and forming two main compounds that act as raw materials: 2CaFe2O3 и MgOFe2O3. Breunerite produces a less pure product than a mixture of magnesia and iron oxide, but is more economical to produce.
References
[edit | edit source]- ^ a b c Breunnerite, a variety of Magnesite: information about the mineral breunnerite in the database Mindat.
- ^ 礦物學名詞: (俄英中对照試用本) Mineralogical Terminology (Russian-English-Chinese version). — Beijing: 中國科学院. 編譯出版委員会 Compilation and Publication Committee of Chinese Academy of Sciences, 1956. — 279 p.
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Breunner, August Graf in Mineralienatlas-Fossilienatlas.
- ^ Bulletin of the United States National Museum. No.30. Published under the Directions of the Smithsonian Institution. — Washington: Government Printing Office, 1885.
External links
[edit | edit source]
- Breunnerite, a variety of Magnesite: information about the mineral breunnerite in the database Mindat.
- Breunnerite in database Mineralienatlas
- Breunnerite: Sevastopol stone museum.