May 8 2013
Triplite is a rare phosphate mineral first observed in 1816 from Chanteloube, Limousin, France. It was named after the Greek word triplos, meaning triplex.
Properties of Triplite
The following are the key properties of triplite:
- Cell Data
- Space Group: I2/a
- a = 12.065–12.134
- b = 6.454–6.546
- c = 9.937–9.939
- β = 106.08°-107.09°
- Z = 8
- Crystal Data
- Monoclinic
- Point Group: 2/m
- Crystals are typically very rough, but may have many indistinct forms, to 4 m; usually nodular, massive
- X-ray Powder Pattern: 3.008 (100), 2.525 (81), 4.277 (76), 3.487 (70), 5.175 (34), 3.923 (26), 2.462 (25)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| MnO |
57.63 |
46.8 |
31.56 |
| P2O5 |
31.84 |
31.9 |
31.58 |
| F |
7.77 |
10 |
- |
| -O = F2 |
3.27 |
4.2 |
3.56 |
| CaO |
2.86 |
0.7 |
- |
| FeO |
1.68 |
14.2 |
31.97 |
| MgO |
1.21 |
2.2 |
- |
| Total |
99.72 |
101.6 |
100.00 |
- Optical Properties
- Optical Class: Biaxial (+)
- Pleochroism: Distinct; yellow-brown to reddish brown
- Orientation: Y = b; Z ^ c = –41°
- Dispersion: r > v, moderate to strong
- Absorption: X > Z = Y.
- α = 1.643–1.684
- β = 1.647–1.693
- γ = 1.668–1.703
- 2V(meas.) = 25°–76°
- Estimated Properties
| Electron density |
Bulk density (electron density)=3.52 g/cm3
note: Specific gravity of Triplite =3.67 g/cm3 |
| Photoelectric |
PETriplite = 11.97 barns/electron
U= PETriplite x ρElectron density= 42.18 barns/cm3 |
| Fermion index |
Fermion index = 0.006
Boson index = 0.993 |
| Radioactivity |
Triplite is not radioactive |
How to Identify Triplite
Triplite is black, brownish black, salmon pink, dark brown, or brown in color. It is non-fluorescent, and has subtranslucent to opaque appearance, distinct cleavage, yellowish gray streak and resinous luster. It has uneven fractures, average density of 3.67 g/cm3 and hardness of 5. It can be formed as massive granular structure observed in granite and other igneous rock.
Global Distribution
Triplite is distributed in the following places:
- Limoges and in the La Vilate quarry, near Chanteloube, Haute-Vienne, France
- Hagendorf, and on the Kreuzberg, Pleystein, Bavaria
- Horni Slavkov, Czech Republic
- Mangualde pegmatite, near Mesquitela, Portugal
- Lemnas, Finland
- Varutrask, pegmatite, 15 km northwest of Skelleftea, Vasterbotten, Sweden
- East Kemptville tin mine, Nova Scotia, Canada
- Mica Lode, Fremont Co., Colorado
- White Picacho district, Maricopa and Yavapai Cos., Arizona
- Lord Hill, Stoneham, Oxford Co.,Maine; at the Elk Ridge pegmatite, Custer, Custer Co., South Dakota
- El Criollo pegmatite, Cerro Blanco, Tanti district, 45 km west of C´ordoba, C´ordoba Province, Argentina
Occurrence of Triplite and Useful Mineral Association
Triplite occurs as principal primary phosphate, commonly lithiophilite, in complex zoned granite pegmatites and in hydrothermal tin veins. It is closely associated with quartz, sphalerite, tourmaline, apatite, vivianite, phosphosiderite, triphylite–lithiophilite and triploidite–wolfeite.
References