Spanish jet: something more than gemstone with magical properties
- Institutio Nacional del Carbon (INCAR-CSIC), Oviedo (Spain)
The first reference to the existence of jet in Spain dates back to the 7th century. Due to the magical powers attributed to this stone, it has always been considered a mysterious gem. Spanish jet is now a scarce natural resource. The article gives scientific explanation for the magical properties of Spanish jet. It is a humic coal, black in colour, bright, carves and polishes well and has a remarkably stability on exposure to the air, for centuries. Its composition is almost exclusively organic and FTIR analysis shows a high proportion of aliphatic over condensed aromatic structures. The conventional rank parameters are not applicable as the results are contradictory. Carbon content and rank of organic matter suggest it is a high volatile bituminous coal, which agrees with the reflectance for phlobaphinite, the other maceral of the huminite/vitrinite group in this coal. These contradictory characteristics of Spanish jet are derived from an anomalous high enrichment of hydrogen. During coalification there is an increase in aromaticity which is responsible for the variation in coal rank parameters, carbon content and responsible for the variation in coal rank parameters, carbon content and vitrinite reflectance. The remarkable stability is attributed to the adsorbed hydrocarbons preventing easy access of oxygen. 2 figs.
- OSTI ID:
- 20885664
- Journal Information:
- Energeia (Lexington), Vol. 18, Issue 1; Other Information: isruiz@incar.csic.es
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SPAIN
VITRINITE
HISTORICAL ASPECTS
PETROLOGY
COAL
X-RAY DIFFRACTION
MICROSTRUCTURE
HYDROGENATION
HYDROCARBONS
BITUMINOUS COAL
PHENOLS
HYDROGEN
COALIFICATION
REFLECTIVITY
STABILITY
POLYCYCLIC AROMATIC HYDROCARBONS
COAL RANK
MOLECULAR STRUCTURE
CHEMICAL COMPOSITION
FOURIER TRANSFORMATION
INFRARED SPECTRA
ORGANIC MATTER