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| Titel |
Mineralogical Characteristics of Serpentine jade and Thulite gemminerals from Booyo area, South Korea |
| VerfasserIn |
A. Baatar, Won Sa Kim |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250019464
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| Zusammenfassung |
| The mineralogical and gemological characteristics of the two gem minerals: serpentine jade
and thulite from Booyo Mine area of South Korea were determined. The study of those
minerals were carried out using polarizing microscope for textural study; color set, hardness
pencil set and refractometer for determining physical characteristics; X-ray powder
diffraction for analyzing crystal structure; XRF, ICP-MS, IR-ray, UV-ray and DTA/TGA
analyses for detailed chemistry.
Serpentine jade consists of antigorite, one of the three polymorph of serpentine. It
displayed dark green color with greasy luster and was transparent or semi-transparent.
Magnetite was observed as inclusion in serpentine jade. XRD data confirmed that serpentine
jade from Booyo consists of antigorite. Physical properties of serpentine jade were found as
Ri=1.56, SG=2.57 and H=5-6. Major chemical composition was SiO2 42.49%, MgO 39.08%,
Fe2O3 3.85% and H2O 11.87% and trace elements were Cr (2188 ppm), Ni (1110
ppm) and Ta (108 ppm). The DTA curve for serpentine jade showed endothermic
peak at 755.0oC related with the decomposition of the mineral by expulsion of the
structural water and exothermic peak at 830.1oC related with structural change of
antigorite to olivine. Thulite displayed pink color, and was a variety of clinozoisite. It
showed vitreous luster and was almost opaque. Physical properties of thulite were
Ri=1.69, SG=3.15 and H= 6-6.5. Chlorite was contained in thulite as inclusion. XRD
data of thulite compares well that of clinozoisite. Major composition of thulite was
SiO2 44.35%, Al2O3 22.29%, Fe2O3 2.40%, CaO 21.46%, MgO 7.12%, MnO
0.22% and H2O 1.52%, and trace elements were Sr (1715 ppm), Ni (180 ppm)
and Ta (2030 ppm). DTA curve for thulite showed endothermic peak at 969.1oC
related with the decomposition of the mineral by expulsion of the structural water. |
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