Editorial Feature

Abelsonite – Occurrence, Properties, and Distribution

Jun 3 2014

The mineral Abelsonite was first seen on fracture surfaces in oil shales in the Green River Formation, located in eastern Uintah County, Utah in the year 1975. It is a nickel porphyrin derivative, and it was named after an American physicist, Philip Hauge Abelson.

Properties of Abelsonite

The key properties of Abelsonite are given below:

Cell Data
- Space group: P1 or P1
- a = 8.508(24)
- b = 11.185(27)
- c = 7.299(15)
- α = 9051(15)’
- β = 11408(12)’
- γ = 7959(13)’
- Z = 1

Crystal data
- X-ray powder pattern: 10.9 (100), 3.77 (80), 7.63 (50), 5.79 (40), 3.14 (40), 5.51 (35), 6.63 (30)
- Point group: 1 or 1
- Triclinic

Chemistry
- As per electron microprobe analysis, the Ni content was 11–14%
- IR and mass spectroscopic analysis shows it is composed of nickel porphyrin

Optical properties
- Semi-transparent
- Absorption: strong reddish-brown to reddish-black
- Optical class: [Biaxial.]
- α, β, and γ = n.d.
- 2V(meas.) = n.d.

Estimated properties
- Radioactivity: Not radioactive
- Electron density (bulk) = 1.48 gm/cc
- Photoelectric, PE = 4.28 barns/electron
- Boson index = 0.89
- Fermion index = 0.11
- Specific gravity = 1.40 gm/cc

How to Identify Abelsonite

Abelsonite can be identified in hand specimens, and in the field using the following unique properties: It is pinkish-red, purple, or reddish-brown in color, and it is translucent. It is often found as fragile clusters of crystals, which can be easily deformed, and are non-fluorescent.

It has a sub-metallic lustre, with a density of 1.45 and a hardness of 2 to 2.5 on the Moh Scale.

Global Distribution

Abelsonite is a scarce mineral, predominantly consigned to drill cores from Wosco, Big Pack Mountain Quadrangle in the USA, and other localities near the Mahogany Zone, Green River Formation in Utah’s Uintah County. It is also found in the Piceance Creek Basin of Rio Blanco County in Colorado.

Occurrence of Abelsonite and Useful Mineral Association

The occurrence of this mineral is in Mahogany Zone fracture surfaces in oil shales, and in the form of small aggregates of 1cm sized thin laths or plates.

It has useful associations with pyrite, albite, quartz, mica, orthoclase, dolomite, and analcime.