Editorial Feature

Seelite-Occurrence, Properties, and Distribution

Seelite is a magnesium-dominant, arsenate-bearing analogue of dymkovite. The mineral was named after Paul Seel (1904–1982) and Hilde Seel (1902–1987), American collectors of microscopic minerals, Philadelphia, Pennsylvania, USA.

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 1 mm; 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
    As2O5 6.67 25.52
    As2O3 13.41 -
    H2O 13.40 [7.34]
    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 » 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= 3,262.42 barns/cm3
    Fermion index Fermion index = 0.006858331
    Boson index = 0.993141669
    Radioactivity
     
    GRapi = 2,984,810.91 (Gamma Ray American Petroleum Institute Units)
    Seelite is radioactive

How to Identify Seelite

Seelite can be identified in the field by its yellow color. The appearance of this mineral is transparent to translucent. It is a mineral with a vitreous-glassy luster. The density of seelite is 3.7 g/cm3 and its hardness is 3 approximate to calcite.

Global Distribution

Seelite is widely distributed in the following locations:

  • Iran - In the Talmessi mine, 35 km west of Anarak
  • France - From the Rab´ejac uranium deposit, seven km south-southeast of Lod`eve, H´erault
  • Germany - Black Forest, Endenburg, Heidelwerk copper mine (Schlächtenhaus); Schenkenzell, Böckelsbach valley, Sophia Mine; Wolfach, Rankach valley, Clara Mine

Occurrence of Seelite and Useful Mineral Association

Seelite is often associated with minerals such as annabergite, zaratite, uranospinite and talmessite (Talmessi mine, Iran); zeunerite (Rab´ejac deposit, France).

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

References

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Your comment type
Submit