Seelite - Occurrence, Properties, and Distribution

Seelite, having a monoclinic crystal system, was first discovered in 1993 from Talmissi mine, Iran and Rabejac uranium deposit, Lodeve, Herault, France.

It was named after Paul and Hilde Seel, mineral collectors from Belgium.

Properties of Seelite

The following are the key properties of Seelite:

• Cell Data
  • Space Group: C2/m
  • a = 18.194–18.207
  • b = 7.062–7.071
  • c = 6.661–6.670
  • β = 99.65°-99.70°
  • Z = 2

• Crystal Data
  • Monoclinic
  • Point Group: 2/m
  • Crystals are tabular, flattened on {100} or {001}, or elongated [010], showing {100}, {001}, {010}, {011}, {011}, to 1mm; typically in spherules, rosettes, and divergent needles
  • X-ray Powder Pattern: 9.02 (100), 4.48 (80), 3.01 (60), 2.849 (60), 3.28 (50), 4.90 (40), 4.00 (40)

• Chemical Composition

  Elements	Content 1	Content 2
  UO3	62.43	62.75
  As2O3	13.41	-
  H2O	13.40	[7.34]
  As2O5	6.67	25.52
  MgO	4.09	4.39
  Total	[100.00]	[100.00]

• Optical Properties
  • Optical Class: Biaxial (–)
  • Pleochroism: Strong
  • X = Y = yellow; Z = colorless
  • Orientation:Z ^ c = 5(1)°
  • Dispersion: r (right pointing double angle quotation mark) » v, inclined
  • α = 1.602–1.610
  • β = 1.730–1.737
  • γ = 1.740–1.753
  • 2V(meas.) = 30°–41°
  • 2V(calc.) = 34°–37.5°

• Estimated Properties

  Electron density	Bulk density (electron density) = 3.38 g/cm3 note: Specific gravity of Seelite = 3.70 g/cm3
  Photoelectric	PESeelite = 965.43 barns/electron U = PESeelite x ρElectron density = 3262.42 barns/cm3
  Fermion index	Fermion index = 0.006 Boson index = 0.993
  Radioactivity	Seelite is radioactive

How to Identify Seelite

Seelite can be found in a yellow color. It has transparent to translucent appearance, and vitreous luster.

The average density of seelite is 3.7 g/cm³, and its relative hardness is 3.

Global Distribution

Seelite is distributed in the following places:

• Talmessi mine, 35km west of Anarak, Iran
• Rabejac uranium deposits, 7km south-south-east of Lodève, Hérault, France

Occurrence of Seelite and Useful Mineral Association

Seelite occurs as a rare mineral in the oxidation zone of uranium bearing hydrothermal deposits.

It is closely associated with zeunerite, uranospinite, zaratite, talmessite, and annabergite.

References

• Seelite – Mindat
• Seelite Mineral Data – Webmineral
• Seelite.pdf - Rruff Project Website - University of Arizona