• Journal of Conservation Science
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• v.29 no.4
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• pp.345-354
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• 2013

This study analyses geochemistrical, microscopic, mineralogical characteristics of coals which have been collected from in and out of the shipwreck No 1 of Mado island during underwater excavation in Taean. The result from mineralogical and geochemical analysis reveals that the specific gravity of the coals is $1.28g/cm^3$. Considering that coals contains 10% mineral of it and the specific gravity of the pure is $1.15g/cm^3$, it is believed that the collected coals would be lignite or biturminous coal. The X-ray diffraction analysis which displays the peak of $2{\theta}$ is 20~25C degree, proves that the collected coals would be categorised as low rank coal. The collected coals is composed of: 93%-94%(93.5%) of vitrinite maceral group, 5%-6%(5.5%) of exinite maceral group, and 1% of inertinite maceral group. In addition, the average of reflection rate is $R_{mean}$: 0.627 showing that it would be either high volatile bituminous C coal or sub-bituminous C coal. Such result confirms that the coal is sub-bituminous C or high volatile bituminous C coal in accordance with the U.S Bureau of Mine(USBM) classification system. The element analysis reveals that the coal is the coking coal which is grouped as the bituminous coal. Comparative analysis between the coals of Mado Shipwreck No 1 and domestic coals shows that the coals of Mado Shipwreck is similar to the bituminous coal used in the area of Janggi in Pohang city.

• The Journal of the Petrological Society of Korea
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• v.17 no.3
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• pp.154-165
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• 2008

Rock bowls and pots used in restaurants are one of the popular usages of natural rocks in Korea. Most rock bowls and pots are made of Mg- and Ca-rich amphibolite composed of hornblende, actinolite, tremolite, diopside, plagioclase. Hornblende occurs as prismatic crystal habit, and belongs to Mg-hornblende to tschermakite. Actinolite and tremolite occur as acicular form (aspect ratio $0.10{\sim}0.13$), and ranges 0.65 to 0.90 in Mg/(Mg+Fe) ratio. These acicular actinolite and tremolite are non-asbestos minerals. However to use of rocks containing these minerals as tableware it is needed to regulatory guidelines for stability and utility based on petrological and mineralogical characteristics. Discrepancy of rock occurrence and mineral chemistry between commercial rock bowls and original rocks indicate that most rock bowls are made of uncertain amphibolite in original location. Consequently, there is a potential risk to use inappropriate amphibolites as tableware. Therefore, it is needed to systematically research on geology and biology, and manage commercial rock bowls and pots used in Korean restaurants.

• Journal of the Mineralogical Society of Korea
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• v.26 no.2
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• pp.129-138
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• 2013

River bank filtration has been considered as a promising alternative water management scheme, in which groundwater is extracted from an aquifer near a river after infiltration of the river water into the aquifer, thereby improving and maintaining the quality of water recovered. Iron (Fe) associated with sediment in contact with groundwater and infiltrating surface water is an important factor in determining the quality of water recovered from the pumping wells in river bank filtration. This study reports the results of Fe speciation in the aquifer sediment samples collected from different depths at the river bank filtration site in Changwon, studied using four different chemical extraction methods, namely, ferrozine, oxalate, HCl, and DCB methods. Overall, the results show that Fe(II) as well as the total Fe content decreases with depth down to ~20 m and then increases further below. This trend is consistent with the redox characteristics suggested by visual observation. The silt/clay size fraction (${\phi}$ < 62.5 ${\mu}M$) has up to 2~10 times more Fe compared with the sand size fraction (62.5 ${\mu}M$ < ${\phi}$ < 2 mm), depending on the extraction method. Of the four extraction methods, DCB solution extracted the most Fe from the sediment samples. The amounts of Fe extracted by the different extraction methods can be a good indicator of the redox conditions along the depth of the aquifer.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.385-393
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• 2009

The spectroscopic characteristics of Madagascar tourmaline were investigated by UV-Vis and FTIR spectroscopy. Physical features were similar to other region's tourmalines. The green and blue samples showed strong absorption band in the 714~743 nm due to $Fe^{3+}$, pink samples showed strong absorption band in the 510~530 nm due to $Mn^{3+}$, brown samples showed strong absorption at 324 nm due to $Mn^{2+}-Ti^{4+}$ IVCT and the colorless samples only revealed weak absorption at 406~413 nm or no absorptions due to low quantity of Mn. Combination of the stretching and bending mode cationic hydroxyl units (metal-OH) are observed in the 4300~4500 $cm^{-1}$. The parallel tube-shaped inclusions which contain hematite were detected generally. This investigation revealed that Cu was not detected but Fe and Mn were detected in the Madagascar tourmalines, and the various colors appear according to the amount of those impurity elements.

• Korean Journal of Heritage: History & Science
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• v.45 no.1
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• pp.102-121
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• 2012

The purpose of this study is to verify homoteneity of soil and earthenwares and identify firing temperature of earthenwares excavated from Yeoncheon Hapsuri: two earthenwares of the New Stone Age(YCP-1, YCP-2); two of the Bronze Age(YCP-3, YCP-4); and four of the Three States Age(YCP-4~8). The comparative analysis of soil (YCRM) and the earthenwares displays that soil geochemical patterns were similar to YCP-1, YCP-3, YCP-5, YCP-6, YCP-7 and YCP-8. On the other hand, YCP-2 and YCP-4 did not show the similarity to the one of soil because they had been enriched with MgO by contained talc and chlorite. Based on the absorption rate, specific gravity, structural characteristics and XRD analysis, firing temperature has been estimated: for YCP-7 and YCP-8 was $870^{\circ}C$ or over; for YCP-2 and YCP-4 $800^{\circ}C$ or below; and for YCP-1, YCP-3, YCP-5 and YCP-6 between 800 and $870^{\circ}C$. Mineralogical analysis displays that the geochemical pattern of the soil is coincide with the one around Yeoncheon Hapsuri site, which also shows similarity to the one of earthenwares. Such result persuades that the excavated earthenwares were produced with the soils within the precinct of the archaeological sites.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.465-475
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• 2022

The seafloor massive sulfide deposits are important mineral resources for base and precious metals, and their ore genesis and metal contents are mainly controlled by wall-rock leaching process and/or magmatic volatile input from the underlying magma chamber. However, the contribution of two different metal sources to the seafloor hydrothermal mineralization significantly varies in diverse geological settings and thus still remains controversial. In this review, mineralogical and geochemical characteristics of SMS deposits from mid-ocean ridges (MORs) and volcanic arcs were investigated to understand the contribution from different metal sources and to suggest future challenges that need to be addressed. As a result, the genetic occurrences of enargite and cubanite, galena and barite indicate the effects of magmatic input and water-rock interaction, respectively. Also, the distributional behaviors of Co, As, and Hg in pyrite and FeS content of sphalerite could be useful empirical indicators to discriminate the significant roles of different metal sources between MOR and Arc settings. To date, as most studies have focused on sulfide samples recovered from the seabed, further studies on magmatic sulfides and sulfate minerals are required to fully understand the genetic history of SMS deposits.

• Economic and Environmental Geology
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• v.57 no.4
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• pp.387-396
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• 2024

The geological disposal of high-level radioactive waste (HLW) involves permanently isolating the wastes in stable geological formations deep underground. Mudstone (siltstone and claystone) containing abundant clay minerals is proposed as a host rock for geological disposal of HLW because clay minerals have low permeability and high ion sorption/exchange capacity. Despite the widespread occurrence of sedimentary basins in Korea, there is a lack of evaluation of mudstone as host rocks for geological disposal. In this study, we utilized the JBH-1 borehole (7-754 m) obtained from the Jinju Formation to investigate the distribution trend and mineral compositions of mudstone. Additionally, we conducted comparative analyses with the Opalinus Clay in Switzerland considered as host rock of geological disposal of HLW. Claystone containing more than 40% clay minerals exhibit thick layers primarily in the upper section (7-350 m) of the JBH-1 borehole. While the clay minerals content of claystone does not show significant variation with depth, there are differences in the characteristics of feldspar and carbonate minerals. These mineralogical variations can led change in pore water chemistry and rock mechanical properties. The clay minerals content of claystone in the Jinju Formation is similar to that of the Opalinus Clay. However, there are notable differences in clay minerals composition. While the Opalinus Clay contains smectite-illite mixed-layer minerals, the Jinju Formation are dominated by illite indicating higher burial temperatures. This information will be useful for studying the host rock of HLW geological disposal site in Korea.

• Journal of the Mineralogical Society of Korea
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• v.28 no.3
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• pp.255-263
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• 2015

To investigate the effect of the weathering process of biotite on Cs sorption, sorption experiment of Cs with $10^{-3}M$ solution was carried out on the biotite reacted at different reaction times at pH 2 and 4, and 1 M solutions of Na, K, Ca, Mg, Rb, and Cs. Peak changes were observed for some samples by XRD, indicating that new mineral phase formed by biotite weathering. Among several factors, cations in solutions have the most significant influence on the mineralogical changes. The samples reacted with Na showed the most outstanding change with increasing peak width and appearance of $12{\AA}$ peak and $14{\AA}$ peak. This new peaks indicate the formation of hydrobiotite and vermiculite. The new peaks had stronger peak intensity for the sample reacted at pH 4 than that at pH 2, probably due to the fast dissolution of small particles and edges and resultant decrease in the formation of expandable layers. The biotite reacted at Mg solution showed small intensity at $14{\AA}$. Based on XRD results, the degree of biotite weathering was in the order of Na, Mg, and Ca. The samples reacted with K, Rb, Cs solutions did not show noticeable mineralogical changes caused by weathering. The amount of sorbed Cs on weathered biotite showed close relationship with the degree of weathering indicated by XRD. At both pH 2 and 4, the biotite reacted with Na solution showed the highest Cs sorption, and those with Mg and Ca solutions showed the next highest ones. The sorbed amounts of Cs on the bitote reacted with K, Rb, Cs solutions were relatively low. This indicates that at the Cs concentration ($10^{-3}M$) which we used for this experiment and which was much higher than the maximum Cs concentration sorbed on the frayed edge site, expandable layer plays more important role than frayed edge. In the cases of K, Rb, and Cs solutions, Cs sorption was decreased because K is the same cations as the one in the interlayer or the sorption of Rb and Cs on the frayed edge prevents the formation of expandable layers.

• Journal of the Mineralogical Society of Korea
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• v.31 no.4
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• pp.267-275
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• 2018

The purposes of this study were to analyze the mineralogical characteristics of slaked lime used for wall repair of traditional buildings in Bagan, Myanmar and to evaluate the physical properties of lime plaster produced by the same method as Bagan region. In the X-ray diffraction and thermal analysis of the Myanmar slaked lime, portlandite ($Ca(OH)_2$) and brucite ($Mg(OH)_2$) were detected as main constituent minerals, and a carbonate rock mainly composed of dolomite ($CaMg(CO_3)_2$) minerals may be used as a raw material to make slaked lime. The field-emission scanning electron microscope analysis showed that the Myanmar slaked lime was composed of irregularly shaped crystals of $0.5{\mu}m$ or larger and a small amount of $0.1{\mu}m$ of plate - like crystals. The size and uniformity of crystals in Myanmar lime is different from that of Korea slaked lime. This may be attributed to the effect of the mineral composition and the lime hydration method of Myanmar, which produces slurry by immersing the burnt lime in excess water for a long period of time. The compressive strength of the lime plaster in Myanmar resulted in a mean value of $1.13N/mm^2$ for the specimens cured for 28 days. The strength of the specimens with Bale juice was $1.03N/mm^2$, respectively. The lime is an air setting material that exhibits strength through long carbonation process. Therefore, it is necessary to evaluate physical properties according to curing period through long-term curing over 28 days in the future.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.421-430
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• 2014

In this study, a series of autoclave experiments were conducted in order to investigate the geochemical and mineralogical effects of carbon dioxide on deep subsurface environments. High pressure and temperature conditions of $50^{\circ}C$ and 100 bar, which are representative environments for geological $CO_2$ sequestration, were created in stainless-steel autoclaves for simulating the interactions in the $scCO_2$-groundwater-mineral reaction system. Zeolite, a widespread mineral in Pohang Basin where many researches have been focused as a candidate for geological $CO_2$ sequestration, and groundwater sampled from an 800 m depth aquifer were applied in the experiments. Geochemical and mineralogical alterations after 30 days of $scCO_2$-groundwater-zeolite sample reactions were quantitatively examined by XRD, XRF, and ICP-OES investigations. The results suggested that dissolution of zeolite sample was enhanced under the acidic condition induced by dissolution of $scCO_2$. As the cation concentrations released from zeolite sample increase, $H^+$ in groundwater was consumed and pH increases up to 10.35 after 10 days of reaction. While cation concentrations showed increasing trends in groundwater due to dissolution of the zeolite sample, Si concentrations decreased due to precipitation of amorphous silicate, and Ca concentrations decreased due to cation exchange and re-precipitation of calcite. Through the reaction experiments, it was observed that introduction of $CO_2$ could make alterations in dissolution characteristics of minerals, chemical compositions and properties of groundwater, and mineral compositions of aquifer materials. Results also showed that geochemical reactions such as cation exchange or dissolution/precipitation of minerals could play an important role to affect physical and chemical characteristics of geologic formations and groundwater.