• Title/Summary/Keyword: polarization microscope

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A Scientific Study of Roof Tiles in Joseon Dynasty from Dongdaemoon Stadium (동대문운동장유적 출토 조선시대 기와의 특성 연구)

  • Chung, Kwang-Yong
    • Korean Journal of Heritage: History & Science
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    • v.45 no.3
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    • pp.160-173
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    • 2012
  • Roofing tile research conducted in Korea so far is mostly related to studies on roofing tile patterns excavation report on the roof tile klin site in the aspects of archeology architecture and history of art. There have been continuous studies on kiln ground and manufacture techniques of roofing tiles. However it is difficult to find roofing tiles research based on scientific experiments. The research on this paper performs physical and chemical experimental study to understand order, manufacturing techniques and other characteristics of Chosun Dynasty roofing tiles excavated in Dongdaemun stadium. As for physical experimental study water absorption, specific gravity, whole-rock Magnetic susceptibility rate and Differential Thermal Analysis are conducted. As for chemical experimental study, neutron activation analysis(NAA), microstructure observation, X-ray diffractometry(XRD) analysis are conducted. Result of neutron activation analysis and statistical analysis on piece of roof tile 22 samples clearly show that the roofing tile samples are from different time line and places. It also shows different composition when compare average value of rare earth resources per findspots. It means roofing tiles were manufactured from clay mineral from several places. Close inspection using XRD and polarization microscope reveals that main components of roofing tiles are quartz and felspar. Mica and Illite are found partially. XRD analysis shows mullite mineral composition which occurs when roofing tile is calcined around $1000^{\circ}C$. Differential thermal analysis shows gradual exothermic peak near $900^{\circ}C$. Based on these results, it is assumed that roofing tile is made at $900{\sim}1000^{\circ}C$. result of XRD analysis shows mullite were made near $1000^{\circ}C$. in Differential Thermal Analysis shows gradual exothermic peak near $900^{\circ}C$. this results shows that roof tiles were made near 900~1000 near $1000^{\circ}C$ mean value of whole-rock Magnetic susceptibility rate. When performed comparative analysis using whole-rock Magnetic susceptibility rate average value, findspots provided no certain classification to arrange. Nonetheless low whole-rock Magnetic susceptibility rate 0.2~0.78(${\times}103$ SI unit) is found when roofing tile patterns are Pasangmun, Taesangmun, Eosangmun, Kyukjamun, Heongsunmun. Overall absorptivity is 14~21%. It is similar to 14~18% of roofing tile from Chosun Dynasty. There is only 1.4~2.5g/cm3 of roof tile sample specific gravity. The analysis finds no difference in specific gravity by findspots.