JTW's Evolutionary Origins - Author: Wachtershauser, Gunter
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Chirality in Pyrite and Pyrite-pulled Products
[pp. 116-117]
According to Bayliss (1977, 1989) there are at least two different types of pyrite:
- High temperature formation pyrite:
- With a cubic crystal structure space group Pa3.
- No optical activity or anisotropy.
- These pyrites are formed in magmatic ore bodies or metamorphic rocks.
- In this form the S2+ groups are assumed to resonate completely making all iron-sulphur bonds equivalent to each other.
- With a cubic crystal structure space group Pa3.
- Low temperature formation pyrite:
- non-cubic crystal structure
(space group P1 [enantiomorphic] or Pca2,1 [Orthorhombic, non-enantiomeric but enantiopolar])
- Demonstrating optically anisotropic activity.
- These pyrites are formed in sedimentary rocks and hydrothermal ore deposits.
- This form is assumed to result from an inhibition of resonance, with non-equivalent sulfur atoms in each S2 unit, resulting in a deformed crystal structure.
- non-cubic crystal structure
(space group P1 [enantiomorphic] or Pca2,1 [Orthorhombic, non-enantiomeric but enantiopolar])
"It is here argued that each of these two possible space groups of low-temperature pyrite offers a simple solution to the problem of biochirality."
- Wachtershauser, Gunter
- Groundworks for an Evolutionary Biochemistry: The Iron-Sulphur World
- Progress in Biophysics and Molecular Biology: Vol. 58, No. 2, pp.85-202
- 1992
- [Pubmed]
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