Abelsonite

Abelsonite

Abelsonite from the Green River Formation, Uintah County, Utah, US
General
Category Organic minerals
Formula
(repeating unit)		 C31H32N4Ni[1]
Strunz classification 10.CA.20
Dana classification 50.4.9.1
Crystal system Triclinic
Unit cell a = 8.508 Å, b = 11.185 Å
c=7.299 Å, α = 90.85°
β = 114.1°, γ = 79.99°
Z = 1[1]
Identification
Color Pink-purple, dark greyish purple, pale purplish red, reddish brown
Crystal symmetry Space group: P1 or P1
Point group: 1 or 1[1]
Cleavage Probable on {111}[1]
Fracture Fragile[2]
Mohs scale hardness 2–3
Luster Adamantine, sub-metallic
Streak Pink
Diaphaneity Semitransparent[1]
Optical properties Biaxial[1]
Ultraviolet fluorescence Non-fluorescent[2]
Absorption spectra Strong reddish brown to reddish black[1]
References [3]

Abelsonite is a nickel porphyrin mineral with chemical formula C31H32N4Ni. It was discovered in 1969 in the U.S. State of Utah and described in 1975. The mineral is named after geochemist Philip H. Abelson. It is the only known crystalline geoporphyrin.

Description

Abelsonite is semitransparent and pink-purple, dark greyish purple, pale purplish red, or reddish brown in color.[1][3] The mineral occurs as thin laths or plates or small aggregates up to 1 cm (0.39 in).[1] The mineral is soluble in benzene and acetone and is insoluble in water, dilute hydrochloric acid, and dilute nitric acid.[4]

Occurrence and formation

The mineral is known only from the Parachute Creek Member of the Green River Formation.[5] It has been known from the Uinta Basin in Utah since its discovery and from the Piceance Basin in Colorado since 1985.[5] Abelsonite occurs in association with albite, analcime, dolomite, mica, orthoclase, pyrite, and quartz.[1]

Abelsonite is a secondary mineral that formed in fractures, vugs, and bedding planes of oil shale.[1][5] The mineral probably formed from diagenesis of chlorophyll, likely chlorophyll a, which was transported as an aqueous solution into a favorable geologic setting.[5][6]

In 2003, abelsonite was fully synthesized for the first time.[7]

Structure

Structure of abelsonite

As of 1989, abelsonite was the only known geoporphyrin to have a crystalline structure.[5][lower-alpha 1] Most geoporphyrins occur as a series of homologues spanning a large range of carbon numbers.[5] The porphyrin which comprises abelsonite is common, but it does not usually occur in isolation from other porphyrins.[8]

The mineral is a deoxophylloerythroetioporphyrin (DPEP), with nickel occupying the center of the porphyrin ring. Most of the mineral consists of a C31 porphyrin with small quantities of a C30 norisomer.[9] The mineral crystallizes in the triclinic crystal system.[1]

History

The mineral was first noted in 1969 in a core sample made by the Western Oil Shale Corporation in Uintah County, Utah.[10] It was described in 1975 in the journal Geological Society of America Abstracts with Programs.[11] The mineral was named after Philip H. Abelson (1913–2004), a long-time editor of the journal Science,[5] for his work in organic geochemistry.[12]

Type specimens are held in The Natural History Museum in London and the National Museum of Natural History in Washington, D.C.[1]

Notes

  1. ↑ So far as the authors were aware[5]

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (eds.). "Abelsonite" (PDF). Handbook of Mineralogy. Chantilly, VA: Mineralogical Society of America.
  2. 1 2 "Abelsonite". Webmineral. Retrieved January 2, 2013.
  3. 1 2 "Abelsonite". Mindat. Retrieved December 21, 2012.
  4. ↑ Milton et al. 1978, p. 932.
  5. 1 2 3 4 5 6 7 8 Mason, Trudell & Branthaver 1989, p. 585.
  6. ↑ Mason, Trudell & Branthaver 1989, p. 594.
  7. ↑ Zhang & Lash 2003, p. 7253.
  8. ↑ Mason, Trudell & Branthaver 1989, p. 593.
  9. ↑ Storm et al. 1984, p. 1075.
  10. ↑ Milton et al. 1978, pp. 930–931.
  11. ↑ Fleischer, Michael (May–June 1976). "New Mineral Names" (PDF). American Mineralogist 61 (5–6): 502.
  12. ↑ Milton et al. 1978, p. 931.
Bibliography

External links

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