• Proceedings of the Mineralogical Society of Korea Conference
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• 2002.05a
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• pp.103-105
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• 2002

• Proceedings of the KSEEG Conference
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• 1999.04a
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• pp.137-139
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• 1999

• Proceedings of the KSEEG Conference
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• 2002.04a
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• pp.335-337
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• 2002

• Proceedings of the Mineralogical Society of Korea Conference
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• 2004.05a
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• pp.96-98
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• 2004

• Proceedings of the Petrological Society of Korea Conference
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• 2009.05a
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• pp.3-3
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• 2009

• Proceedings of the Mineralogical Society of Korea Conference
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• 2003.05a
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• pp.60-62
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• 2003

• Journal of the Mineralogical Society of Korea
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• v.16 no.1
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• pp.19-31
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• 2003

Chemical composition, crystal structure, refractive index, specific gravity, color, and luster were studied fur pyrope-almandine series garnets. The main coloring agents determining the reddish or brownish garnets were also investigated. It was also examined if there is any relationship between mineralogical properties with respect to the various chemical compositions in the solid solution, in the hope to figure out the existing classification values of R.I. and S.G. using gem- testing facilities to distinguish pyrope from almadine. It was found that 17 out of the 24 specimens belong to pyrope and the rest almandine. R.I. of pyrope goes up to 1.77 and that of almandine is higher than the value.5.5. of pyrope reaches to 3.88 and that of almandine is greater than the value of pyrope. X-ray diffraction data revealed that pyrope-almandine garnets are isometric with space group Ia3d, and also show that the variation of cell parameters are not significant enough to parallel with the chemical compositions of the series. R.I. and S.G. increase with FeO content. Fe and Mn are most responsible to the red-purple and orange coloration of the specimens, respectively. Both zircon and rutile crystals are most common inclusions in the reddish stones.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.359-370
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• 2009

Arsenic and heavy metals leached out as a result of oxidation of tailings exposed to the surface pose a serious environmental contamination of mine areas. This study investigated how arsenic behavior is controlled by a variety of processes, such as oxidation of sulfides and formation or alteration of secondary minerals, based on mineralogical methods. The study was carried out using the tailing samples obtained from Nakdong mine located in Jeongseongun, Gangwondo. After separating magnetic and non-magnetic minerals using pretreated tailing samples, each mineral sample was classified according to their colors and metallic lusters observed by the stereoscopic microscope. Subsequently, the mineralogical properties were determined using various instrumental analyses, such as x-ray diffractometer (XRD), energy dispersive spectroscopy (EDS), and electron probe micro analyzer (EPMA). The literature review confirmed that various ore minerals were identified in the Nakdong ore deposits. In this study, however, there were observed a few original ore minerals as well as secondary and/or tertiary minerals newly formed as a result of weathering including oxidation. In particular, we did not recognize pyrrhotite which has been known to originally exist in a large abundance, but peculiarly colloform-type iron (oxy)hydroxides were identified, which indicates most of pyrrhotite has been altered by rapid weathering due to its large reactivity. In addition, a secondary scorodites filling the fissure of weathered primary arsenopyrites were identified, and it is speculated that arsenic is immobilized through such a alteration reaction. Also, we observed tertiary iron (oxy)hydroxides were formed as a result of re-alteration of secondary jarosites, and it suggests that the environment of tailing has been changed to high pH from low pH condition which was initiated and developed by oxidation reactions of diverse primary ore minerals. The environmental change is mainly attributed to interactions between secondary minerals and parental rocks around the mine. As a result, not only was the stability of secondary minerals declined, but tertiary minerals were newly formed. As such a process goes through, arsenic which was immobilized is likely to re-dissolve and disperse into surrounding environments.

• Mineral and Industry
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• v.16 no.1
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• pp.1-16
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• 2003

수천 년 전부터 인간생활에 이용되어온 일라이트-운모는 다른 광물자원에 비하여 사용량은 많지 않지만, 요업, 도료, 종이, 건축용 재료, 화장품 소재 및 전자부품과 전기 재료 등 여러 산업 분야에 널리 사용되고 있다. 일라이트-운모는 광물학적으로 같은 계열의 광물군임에도 불구하고 산출상태, 입도 및 용도의 차이에 따라 다른 광물자원으로 취급되고 있다. 특히 국내에서 일라이트는 용어상의 혼란과 불명확한 법정 등록광종 때문에 효율적인 자원관리와 연구개발이 곤란한 실정이다. 그러므로 일라이트를 비롯한 점토광물 자원에 대한 광업법규상의 개선과 제도적 정비가 시급히 요구된다. 국내에서 개발되고 있는 일라이트-운모의 광석 유형은 그 광물상과 산출상태에 따라 페그마타이트상 백운모, 운모편암상 백운모, 납석상 일라이트 및 점토상 일라이트로 구분된다. 일라이트와 운모는 서로 다른 용도로 사용되고, 그 용도에 따라 그 품위 및 품질 개념이 다르다. 일라이트-운모 광석의 품위 및 품질 면에서 가장 기본적인평가방식은 (1) 육안 및 편광현미경 관찰, (2) X-선회질 분석 및 (3) 화학분석인 것으로 생각된다. 특히 리트벨트법을 응용한 X-선회질 정량분석법은 일라이트의 품위를 산정하는데 유력한 수단이 될 수 있을 것으로 여겨진다. 국내 일라이트-운모 자원의 자원잠재성과 부가가치를 향상시키기 위해서는 광석에 대한 정확한 품위 평가를 바탕으로 가장 적절한 이용 분야를 모색해야 할 것으로 판단된다.

• Journal of the Mineralogical Society of Korea
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• v.32 no.1
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• pp.63-69
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• 2019

The oxidation states of structural Fe in minerals reflect the paleo-depositional redox conditions for the biologically or abiotically induced mineral formation. Particularly, nano-scale analysis using high-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) is necessary to identify evidence for the microbial role in the biomineralization. HRTEM-EELS analysis of oxidation states of structural Fe and carbon bonding structure differentiate biological factors in mineralization by mapping the distribution of Fe(II)/Fe(III) and source of organic C. HRTEM-EELS technique provides geomicrobiologists with the direct nano-scale evidence of microbe-mineral interaction.