Editorial Feature

Attakolite – Occurrence, Properties, and Distribution

Sep 5 2013

Attakolite has been named after the Greek word for salmon, for its pale red color.

Properties of Attakolite

The following are the key properties of attakolite:

Cell Data
- Space group: C2/m
- a = 17.188(4)
- b = 11.477(8)
- c = 7.322(5)
- β = 113.83(4)°
- Z = 4.
Crystal Data
- Monoclinic
- Point group: 2/m
- Indistinctly crystalline, massive
- Twinning: possible twin lamellae are observed in thin section
- X-ray powder pattern: 3.09 (10), 3.13 (8), 4.34 (7), 2.97 (6), 6.61 (4), 5.68 (4), 3.51 (4).

Chemical Composition

Elements	Content 1	Content 2
SiO₂	9.35	5.9
Al₂O₃	26.97	26.8
Fe₂O₃	0.60	3.9
FeO	1.31	-
MnO	7.10	9.7
PbO	0.03	-
MgO	0.29	-
CaO	11.40	6.6
SrO	3.30	3.0
Na₂O	0.03	-
F	0.10	-
Cl	0.06	-
H₂O⁺	5.92	[10.5]
H₂O^-	0.20	-
CO₂	0.57	-
P₂O₅	32.59	33.6
SO₃	0.13	-
-O=(F,Cl)₂	0.06	-
Total	99.89	[100.0]

Optical Properties
- Transparent
- Color: white to pale red; colorless in thin section
- Optical Class: Biaxial(+)
- Orientation: Y = b; Z = c; X ^ a = 24°
- Dispersion: r>v, strong
- α = 1.650-1.655; β = 1.654-1.664; γ = 1.661-1.675
- 2V(meas) = 75-84°; 2V(calc) = 74°.

Estimated Properties

Electron density	Bulk density (electron density) = 3.11 g/cm³ note: Specific gravity of attakolite = 3.16 g/cm³
Photoelectric	PE_Attakolite = 7.52 barns/electron U = PE_Attakolite x ρ electron density = 23.39 barns/cm³
Fermion index	Fermion index = 0.00403828 Boson index = 0.99596
Radioactivity	Attakolite is not radioactive.

How to Identify Attakolite

Attakolite appears as a white to pale red mineral, colorless in thin sections. Attakolite has a hardness of 5.

Global Distribution

Attakolite is found in the Vastana mine, near Nasum, Skane, Sweden.

Occurrence of Attakolite and Useful Mineral Association

Attakolite occurs in iron deposits. This mineral is associated with berlinite, lazulite, trolleite, apatite, svanbergite, prophyllite, hematite, calcite and quartz.