• Journal of the Korean Chemical Society
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• v.7 no.2
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• pp.153-158
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• 1963

A review of the literature is cited. Little exact information exists on the relation between clay materials and talc. The raw materials which are used in making steatite body consist of talc, clay, feldspar, and flint mined in Korea. The percentage absorption and linear burning shrinkage are measured and then discussed. The vitrified bodies were used in measurement of dielectric properties. The method of measurements for dielectric properties are described too.

• Journal of the Mineralogical Society of Korea
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• v.11 no.2
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• pp.69-84
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• 1998

The Daehyun sericite deposit in socheon-myun, Bongwha-gun, Kyungsangbuk-do, Korea, has been formed by the hydrothermal alteration of the Hongjesa granite of Precambrian age, leaving the muscovite granite between ore body and the Hongjesa granite as the wall rock alteration zone. The process of sericitization of granitic rock as well as chemistry and structures of sericites were studied using polarizing microscope, X-ray diffractometer (XRD), electron probe microanalyzer (EPMA) and high resolution transmission electron microscope (HRTEM). There are two genetic types of sericites having different chemistry and structure. The early sericite is of 2M1 polytype and has octahedral composition close to muscovite. It has been formed from the primary muscovite, tourmaline and quartz under a relatively high temperature. The late sericite is of 1M, 2M1 and 3T polytypes and has phengitic composition. It has been formed form feldspar, biotite, muscovite and tourmaline under a relatively low temperature. Chemical analyses show t, the early sericite has less Mg+FeT content and lower Si/AlIV ratio in tetrahedral site than the late sericite.

• Journal of the Korean Ceramic Society
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• v.31 no.1
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• pp.47-54
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• 1994

The fundamental studies for exploit natural resources was investigated on Uljin pottery stones that estimated the amount of mineral deposits at 350 million tons. The results obtained are as follows; In the chemical composition of Uljin pottery stones the amount of Al2O3 are a little compared with other pottery stones and that of Na2O and K2O are a large. Fe2O3 content is lower than 0.3 wt%, thus whiteness of its is 83. The major minerals composition of Uljin pottery stones are quartz and feldspar mineral. The refractoriness (SK) of its is 14. Lattice constants of quartz in Uljin pottery stones are 4.8865 $\AA$ in a-axis and 5.3852 $\AA$ in c-axis. Lattice constants were expanded by HCl treatment and sintering. Microstructures of Uljin pottery stones are linked up with the crystal particles under 10 microns in size.

• 보존과학연구
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• s.28
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• pp.39-58
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• 2007

The Seated Buddha image carved on rock surface of Yuneulgok in Bae-ri, Gyeongju constituted of alkali feldspar granite. There is surface weathering by abrasion, exfoliation and break out. As a result various experiment was carried out testing rock material property to quantitatively grade weathering. Besides, this study is focused on properties of rock and correlation between things. Additionally, comparison of chemical properties to nondestructive weathering grade in the buddha image carved on rock. This result utilized on important resource for scientific conservation system compared with weathering appearance.

• Journal of the Korean Ceramic Society
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• v.11 no.3
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• pp.3-13
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• 1974

In order to clarify, factors affecting on mechanical strengthof porcelain bodies, some experiments were carried out for bobies consisting of Hadong kaolin, quartz of optical glass grade and potash-feldspar. At first, degree of vitrification of the fired bodies were examined from the results of bulk density measurement. Constituent minerals of these fired bodies were mainly examined by means of X-ray diffraction, and their microstructure were observed by means of the polarization microscope and scanning electron microscope. Transverse and impact strength of the bodies were also determined. Finally, relations between their mechanical strength and the other properties obtained were discussed. The mechanical strength, at least the transverse strength increased with increasing densification of the bodies and accompanied with an increase of stress produced in the quartz grains and, perhaps other phases composing the bodies.

• Journal of the Korean institute of surface engineering
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• v.26 no.6
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• pp.334-340
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• 1993

The physico-chemical properties and characteristics after thermal treatment of natural zeolite from Kampo area were studied. The physico-chemical properties of natural zeolite were studied by investigating chemical composition, x-ray diffraction pattern(XRD), scanning electronic microscope(SEM), infrared spec-tra(IR), thermal analysis(TA), and cation exchange capacity(C.E.C.), and the characteristics of natural zeo-lite after thermal treatment from $400^{\circ}C$ to $900^{\circ}C$ were compared with the natural zeolite. This study showed that clinoptilolite was the predominant costituent in natural zeolite, and the natural zeolite contained a little amount of quartz and feldspar as impurities. Zeolite mineral was seen to develop slowly by the natural alternation of volcanic ash considering the almost amorphous crystal structure. The more temperature of ther-mal treatment increased, the more adsorption capacity decreased, considering the fact that the hydroxy peak diminished on infrared spectra, and that cation exchange capacity also decreased distinctly.

• Journal of Conservation Science
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• v.35 no.1
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• pp.91-98
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• 2019

The fragments of a wall painting excavated from among the historical remains of Jeseoksa Temple in Iksan. The extent of the damage to the fragments was examined and an analysis of the components of the pigment was conducted. The results of the component analysis of the pigment confirmed that the white pigment consisted of alkali feldspar and mullite. Although the results of the visual inspection revealed differences in color in the red and black pigments, the main component of the two colors was confirmed to be iron oxide. Red and black pigments are found at the same position. Although differences of color is obvious, those are identified as hematite and magnetite of oxidized steel's affiliation. It is judged that Differences of ingredients happened by external environment's factors.

• Economic and Environmental Geology
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• v.46 no.2
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• pp.179-198
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• 2013

The Boziguoer A-type granitoids in Baicheng County, Xinjiang, belong to the northern margin of the Tarim platform as well as the neighboring EW-oriented alkaline intrusive rocks. The rocks comprise an aegirine or arfvedsonite quartz alkali feldspar syenite, an aegirine or arfvedsonite alkali feldspar granite, and a biotite alkali feldspar syenite. The major rock-forming minerals are albite, K-feldspar, quartz, arfvedsonite, aegirine, and siderophyllite. The accessory minerals are mainly zircon, pyrochlore, thorite, fluorite, monazite, bastnaesite, xenotime, and astrophyllite. The chemical composition of the alkaline granitoids show that $SiO_2$ varies from 64.55% to 72.29% with a mean value of 67.32%, $Na_2O+K_2O$ is high (9.85~11.87%) with a mean of 11.14%, $K_2O$ is 2.39%~5.47% (mean = 4.73%), the $K_2O/Na_2O$ ratios are 0.31~0.96, $Al_2O_3$ ranges from 12.58% to 15.44%, and total $FeO^T$ is between 2.35% and 5.65%. CaO, MgO, MnO, and $TiO_2$ are low. The REE content is high and the total ${\sum}REE$ is $(263{\sim}1219){\times}10^{-6}$ (mean = $776{\times}10^{-6}$), showing LREE enrichment HREE depletion with strong negative Eu anomalies. In addition, the chondrite-normalized REE patterns of the alkaline granitoids belong to the "seagull" pattern of the right-type. The Zr content is $(113{\sim}1246){\times}10^{-6}$ (mean = $594{\times}10^{-6}$), Zr+Nb+Ce+Y is between $(478{\sim}2203){\times}10^{-6}$ with a mean of $1362{\times}10^{-6}$. Furthermore, the alkaline granitoids have high HFSE (Ga, Nb, Ta, Zr, and Hf) content and low LILE (Ba, K, and Sr) content. The Nb/Ta ratio varies from 7.23 to 32.59 (mean = 16.59) and the Zr/Hf ratio is 16.69~58.04 (mean = 36.80). The zircons are depleted in LREE and enriched in HREE. The chondrite-normalized REE patterns of the zircons are of the "seagull" pattern of the left-inclined type with strong negative Eu anomaly and without a Ce anomaly. The Boziguoer A-type granitoids share similar features with A1-type granites. The average temperature of the granitic magma was estimated at $832{\sim}839^{\circ}C$. The Boziguoer A-type granitoids show crust-mantle mixing and may have formed in an anorogenic intraplate tectonic setting under high-temperature, anhydrous, and low oxygen fugacity conditions.

• Journal of the Mineralogical Society of Korea
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• v.7 no.1
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• pp.62-79
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• 1994

The quanttative and structural analysis of the binary standard mixtures of albite and quartz, and microcline and albite were carried out using the Rietveld refinement method in order to investigate the accuracy and precision of the method. The quantitative analysis using the Rietveld method results in a standard deviation of 4 wt % for the albite-quartz standard mixtures and 1 wt % for the microcline-albite standard mixtures, suggesting that its accuracy is far better than that of the conventional XRD method in which only a few selected peaks are utilized. Furthermore, the unit-cell parameters of component minerals in mixtures were also estimated accurately during the analysis. It was observed that the refined weight fractions deviate systematically from their measured values when the method is applied to the mixtures that contain minerals with different degrees of preferred orientation, such as albite-quartz mixtures. The preferred orientation parameters and R-values suggest that the systematic deviation is caused as a result of the preferred orientation effect of feldspar crystallites. It is evident that the preferred orientation corrections are of help for the accurate determination of unit-cell parameters, although they may not improve the result of quantitative analysis significantly. The refined weight fraction of the mineral with higher degree of preferred orientation in mixture is greater than the measured one. This is apparently caused by the effect of geometry of feldspar crystallites in the surface of the mounted sample. The Rietveld refinement method minimizes the problems inherent in the traditional XRD methods, such as the line overlap, primary extinction, and preferred orientation effect, by fitting every data point in a whole pattern explicitly. Furthermore, accurate unit-cell parameters as well as scale factors that can be obtained from the Rietveld refinement are used for the quqantification. The present stdudy demonstrates that the Rietveld method yields far more accurate analytical result than the conventional XRD quantitative analysis method does.

• The Journal of the Petrological Society of Korea
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• v.21 no.3
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• pp.309-333
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• 2012

Basalt having lots of feldspar phenocryst occurred at the northern and southern slope of the Mt. Halla, Jejudo. Among them, the Sioreum trachybasalt in southern slope consists of abundant phenocrysts of plagioclase in aphanitic groundmass. And the number of plagioclase grains are about 20 per $10cm^2$, and based on 667 grains the sizes are 13~0.7 mm (average 4.23 mm) in length and 8.6~0.5 mm (average 2.3 mm) in width. In according to modal analyses, Sioreum basaltic rock consists mainly of plagioclase (16~28%), olivine, clinopyroxene (1.5~6%) and opaque minerals (~0.1%) of magnetite and ilmenite as phenocryst and microphenocryst and groundmass (60~82%). The compositions of plagioclase, olivine and clinopyroxene are bytownite~andesine, chrysolite~hyalosiderite, augite respectively. Plagioclase phenocrysts show different type of zoning, namely, normal, reversal, patchy, oscillatory type. The An contents of zoned plagioclase mainly increase from core to rim. Those of oscillatory type from core to rim show variations of increase following decrease or decrease following increase, being more enriched in rim or almost same to core. Under the microscope, some plagioclase phenocrysts are especially melted in core part or marginal part, or found as only the remnant remain which resulted from reaction with melt. Some clinopyroxene are also corroded in margin part or found as irregular shape resulted from melting. The characteristics of petrography and compositional variation from core to rim of plagioclase and clinopyroxene, indicate that they are disequilibrium with melt and has been undergone geological environmental changes in magma batch during crystallization including magma mixing with replenishment of more mafic and high temperature melt.