May 20 2014
Ardealite was named after Ardeal, the old Romanian name for Transylvania. It was named by Josef Schadler and Franz Halla in 1931, after it was discovered in Transylvania.
Properties of Ardealite
The following are the key properties of ardealite:
- Cell Data
- Space group: Cc (synthetic)
- a = 5.721(5)
- b = 30.992(5)
- c = 6.250(4)
- β = 117.26(6)°
- Z = 4
- Crystal Data
- Monoclinic
- Point group: m
- Crystals platy and very thin, minute, as thin crusts and fine grained-powdery, pulverulent to clayey masses, generally intimately intermixed with brushite and gypsum
- X-ray powder pattern: 7.73 (100), 3.08 (55), 3.87 (36), 1.810 (27), 2.813 (25), 2.849 (24), 3.93 (21)
- Chemical Composition
| Elements |
Content 1 |
Content 2 |
Content 3 |
| SO3 |
21.25 |
22.75 |
23.26 |
| P2O5 |
21.85 |
21.31 |
20.61 |
| CaO |
31.61 |
31.14 |
32.58 |
| H2O+ |
25.14 |
24.86 |
23.55 |
| Insol |
0.39 |
- |
- |
| Total |
100.24 |
100.06 |
100 |
- Optical Properties
- Semi-transparent
- Color: pale yellow, yellow, brownish-yellow, colorless
- Optical Class: Biaxial (-)
- α = 1.531(2)
- β = 1.539(2)
- γ = 1.546(2)
- 2V(meas) = 86°
- Estimated Properties
| Electron density |
Bulk density (electron density) = 2.37 g/cm3
note: Specific gravity of ardealite = 2.32 g/cm3 |
| Photoelectric |
PEArdealite = 3.84 barns/electron
U=PEArdealite x ρ electron density = 9.11 barns/cm3 |
| Fermion index |
Fermion index = 0.0012845606
Boson index = 0.99871 |
Radioactivity
|
Ardealite is not radioactive
|
How to Identify Ardealite
Ardealite appears as a pale yellow, brownish-yellow, or colorless semi-transparent mineral.
Global Distribution
Ardealite is distributed in the following locations:-
- Romania – from Cioclovina Cave, Transylvania
- Italy – from La Guangola Cave, near Altamura, Apulia
- Bulgaria – from Magurata and Bacho Kuo Caves
- Namibia – from Baobab and Usib Caves
- Australia – from Moora Pave Cave, Jurien Bay
- Japan – from Onino-Iwaya Cave, Hiroshima Prefecture
- Malaysia – from Niah Great Cave, Sarawak
Occurrence of Ardealite and Useful Mineral Association
Ardealite occurs in limestone caves, as an early stage of the breakdown of bat guano, in reaction with calcite.
It is associated with brushite, gypsum, carbonate-hydroxylapatite, newberyite, and taranakite.
References