• Journal of Conservation Science
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• v.34 no.2
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• pp.119-128
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• 2018

This study revealed the material composition and characteristics of 19 glass fragments excavated from stone chamber No. 1 of Jeongchon Tomb in Naju through chemical composition analyses and observations. These characteristics were compared with the characteristics of the glass fragments excavated from No. 3 tomb of Bogam-ri in Naju. The purpose of this study was to identify the characteristics of the ancient glass of the Mahan-Baekje period. The glass fragments excavated from the Jeongchon Tombs can be classified into purplish blue, light-purplish blue, greenish blue, green, and mixture of purple blue and purple, based on their color. These beads were made using a drawn and casting technique. In addition, blue glass fragments were primarily excavated form No. 3 tomb of Bogam-ri. However, red glass fragments were not excavated from either of the tombs. According to chemical composition analyses, soda glass group and potash glass group were common in both the tombs. Additionally, alkali mixed glass group and lead barium glass group were excavated from Jeongchon Tombs and No. 3 tomb of Bogam-ri, respectively. The glass fragments excavated from No. 3 tomb of Bogam-ri have more color variations than those excavated from Jeongchon Tombs.

• Conservation Science in Museum
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• v.13
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• pp.45-49
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• 2012

A scientific analysis was carried out on the 14 pieces of glass beads excavated from the Daho-ri site NO. 6, Changweon. Most of the glass pieces were made of light blue transparent glass with round bubbles aligned in a regular direction. As a result of the SEM-EDS analysis, all the glass pieces turned out to be within the potash glass group (K₂O-SiO₂) and were identified to be the LCA (Low CaO, Low Al₂O₃) series glass, of which the concentration is 5% or below for CaO and Al₂O₃ respectively. In addition, it is presumed that plant materials were refined or a mineral (saltpetre, KNO₃) was used as the raw materials for making potash and also that the ingredient acting as a colorants for light blue color was affected deeply by CuO.

• Journal of Conservation Science
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• v.33 no.5
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• pp.331-344
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• 2017

In this study, glass beads from Osan Sucheong were classified according to color into 10 groups. Among these groups, reddish brown, bluish green, and purplish blue were identified as the main colors of glass beads based on their large quantities in Osan Sucheong. The glass beads of these main colors were then classified according to their chemical compositions and and looked at the changing process. Based on the results, reddish brown and bluish green glass beads can both be divided into five types, and purplish blue glass beads can be divided into four types. Furthermore, according to continuity of type, it was identified as the main attributes that the reddish brown beads belong to two types, whereas the bluish green and purplish blue each belong to one type. Based on a review of primary attributes, beads of these three colors were identified as soda glass and high-alumina glass. The results indicate that these beads came from a single, consistent route of origin into the region. However, it is possible that glass beads came through various routes into Osan Sucheong in the $4^{th}$ century, because many types of chemical compositions have been detected for beads from this time.

• Journal of Conservation Science
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• v.31 no.3
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• pp.255-265
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• 2015

In this study, the potash glass beads of 281 samples in 30 sites analyzed until now were classified according to the chemical composition. And the color, size, manufacturing technique and distribution period were compared. Korea potash glass beads are divided into 3 types depending on the stabilizer content. I, II type is the CaO and $Al_2O_3$ content of less than 5%. Relatively, I type has a high CaO and II type has a high $Al_2O_3$. In contrast, III type comprises more than CaO 5%. I, II type is the saltpetre, III type is estimated using plant ash as row material of flux. A review of the properties by type, I type is cobalt blue, copper blue and purple beads. The outer diameter is sized to the range 1.4~7.4mm. Also it was produced by the drawing technique. It was used continuously from BC 1C until around AD 6C. On the other hand, II type is outer diameter of 1.9~3.6mm and a copper blue beads. manufacturing technique is the same as the I type. This seems to have been in use since around AD 1C to 4C. Finally, III type is brown, colorless, amber beads and an outer diameter of about 10mm. It was formed by winding technique and appeared in the tombs of Goryeo and Joseon Dynasty. As a result, 3 types of potash glass beads distributed in Korea is likely to flowing through the various trade routes from different provenances.

• Journal of Conservation Science
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• v.28 no.3
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• pp.205-216
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• 2012

65 samples of glass bead excavated from Mahan tombs of Asan Bakjimeure site consists of 13 of potash glass group and 52 of soda glass group and soda glass is superior in numbers. When classified according to color, purple blue glass bead is accompanied potash and soda glass group whereas purple glass bead is potash glass group and red, greenish blue, green and gold foil glass bead is soda glass group. Purple blue glass bead is classified as LCA type in which the content of the stabilizer is low. Of this, the soda glass categorized as LMK type with low content of MgO and $K_2O$ is determined that natron is used as the raw material. As to red glass, the homogeneous glass is LCA-B/HMK type and the heterogeneous glass is HCLA/LMK type. Thus, each of these two types are likely to be used plant ash and natron respectively. Greenish blue and green glass depends of the type that round glass is LCA-A/LMHK type and the segmented glass is LCA-B/HMK type. The gold foil glass bead is manufactured by the purity of 19.9~22.6K gold foil and the soda glass of HCLA/LMK type. In other words, the most of the glass bead of Asan Bakjimeure site is similar to the composition of the glass confirmed in other sites of the Baekche period. On the other hand, the greenish blue and green segmented bead and some red round bead is a different chemical composition is considered that the difference in raw materials. These characteristics is expected to be an important evidence for the understanding of the trade system of the ancient glass.

• Korean Journal of Heritage: History & Science
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• v.41 no.1
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• pp.5-19
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• 2008

Thirty six samples of Western asia glass vessel shards which were excavated from South Mound of Hwangnamdaechong were each measured for thickness, pore size and specific gravity and analyzed for ten major compositions and thirteen trace elements. The glass samples with colorless, greenish blue and dark purple blue were well classified by principal component analysis(PCA). All glass shards of Hwangnamdaechong belonged to Soda glass system ($Na_2O-CaO-SiO_2$) which have the range of 14~17% $Na_2O$ and 5~6% CaO. The corelation coefficients of (MgO, $K_2O$) and (MnO, CuO) showed above 0.90. The concentrations of thirteen trace elements apparently differentiated from colorless, greenish blue and dark blue glasses. We found that thirteen trace elements were very important indices for studying raw material of glass and the origin of glass making. Colorless glass : The specific gravity is $1.50{\pm}0.04$. Circle or oval circle pores are observed with regular direction in internal zone and the longest one is about 0.35 mm. The raw material of sodium must be the plant ash because sodium glasses contain HCLA(High CaO, Low $Al_2O_3$) and HMK(high MgO, high $K_2O$) and suggested to Sasanian glass. The total amount of coloring agent of colorless glass is below 1 % which is too small to attribute to the color. Greenish blue glass : The specific gravity is $1.58{\pm}0.04$. The fine pores which are 0.1~0.2mm are dispersed in internal zone. Sodium glasses are distributed to HCLA and HMK. Therefore the greenish blue glass also have used plant ash for raw material of sodium with the same as colorless glass. It was also suggested to the glass of Sasanian. The total amount of coloring agent of greenish blue glass is about 4% under the influence of working MnO, $Fe_2O_3$ and CuO. Dark purple blue glass : The specific gravity is $1.48{\pm}0.19$. There are rarely pores in internal zone. They are distributed to HCLA and LMK(Low MgO, Low $K_2O$) and suggested to Roman glass. The raw material of sodium is estimated to natron. The total amount of coloring agents of greenish blue is about 3% by $Fe_2O_3$ and CuO. These studies for western asia glass shards from South Mound of Hwangnamdaechong could be used in the future as the standard data which could be compared with those of other several graves in Korea and dispersed in foreign areas.

• Conservation Science in Museum
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• v.30
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• pp.71-88
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• 2023

This paper examined the visible characteristics and chemical composition of glass beads from the Joseon Dynasty as well as the associations thereof. It also explored the characteristics and uses of glass beads by region. This study covered a total of 1,819 pieces excavated from 25 locations in the Gyeonggi, Chungcheong, and Gyeongsang regions, of which 537 pieces were analyzed for their chemical composition. Glass beads of the Joseon Dynasty take a variety of shapes such as a Round, Coil, Floral, Segmented, Flat, Oval, and Calabash. Colors vary from shades of brown (brown, lemon yellow) and shades of blue (Bluish-Green, greenish-Blue, Purple-Blue) to shades of white (colorless, white) and shades of green (Green, Greenish-Blue, Greenish-Brown). Brown accounts for the largest percentage, followed by Bluish-Green, greenish-Blue. It was identified that Drawing technique was the most common glass bead production technique of the Joseon Dynasty. Potassium oxide (K₂O) was the most common flux agent for glass beads, while the potash glass and mixed alkali glass groups account for the largest quantity. The choice of stabilizers depended on the type of flux agents used, but the most common were calcium oxide (CaO) and aluminum oxide (Al₂O₃). The potash glass and potash lead glass groups are high in CaO and low in Al₂O₃, the mixed alkali glass group is high in CaO, and the lead glass group is low in CaO. In terms of the association between color and shape, most of the beads with shade of brown and blue have round shapes of brown and blue have spherical shapes, while the coil shape is prominent in blue beads. A high percentage of green and colorless beads also take the shape of a coil, while white beads in general have a floral shape. In terms of the association between shape and chemical composition, round, floral and segmented shapes account for a high percentage of the potash glass group, while coil and flat shapes are common in the mixed alkali glass group. This paper also analyzed the colorants for each color based on the association between color and chemical composition. Iron (Fe) was used as the colorant for brown and white, and titanium (Ti) and iron were used for light yellow. Purple-Blue was produced by by cobalt (Co), and greenish-Blue, Bluish-Green, green, Greenish-Blue were produced by iron and copper (Cu). Colorless beads had a generally low colorant content.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.158-171
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• 2016

The observation and analysis results of 9 glass bead samples collected from Oc Eo site in Vietnam, an outport of the ancient port city Funan in East Asia, are as follows. The type of glass beads is round, the colors are reddish brown, greenish blue, green, black and purplish blue, and the chemical composition is soda glass group. This means that they are similar in type, color and chemical compositions to glass beads from the ancient Korean peninsula. There are limitations in data because the glass beads are not from excavation investigation but from earth surface investigation. But it is significant that similar making technique and chemical composition are being observed in both the glass beads from Oc Eo and those of Korea. According to "Nihon Shoki" Kinmeiki, Baekje king sent Funan's goods and 2 slaves to Japan in 543. It is clear that there were direct or indirect exchanges between Baekje and Funan. The possibility has grown that glass beads could be included among goods.

• Journal of Conservation Science
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• v.36 no.5
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• pp.405-420
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• 2020

A convergence research was conducted on glass beads excavated at the ruins of Hapgang-ri, Sejong, using the archeology and conservation approach. The period of appearance of Jugu Towangmyo in the ruins of Hapgang-ri can be estimated to begin in the late 2^nd century; for Jugu Towangmyo No. 15, the period spans from the late 2^nd to early 3^rd century. Form, color, and manufacturing techniques of complete glass beads were examined, and the cross-sections and chemical composition of 16 samples were observed. Based on these analyses, the glass beads were divided into blue, purple, and red colors. The blue-colored beads could be further sub-divided based on their gloss and brightness; in contrast, the red-colored beads were highly uniform with regard to these parameters. Based on the stripe and bubble arrangement on the surface of the glass beads, their drawing technique was identified. Traces of heat treatment or polishing were observed at the ends of the beads. According to their chemical composition, the 16 samples were classified into 3 potash glass and 13 soda glass groups; in the latter, the properties of the stabilizers were divided according to the blue and red bead colors. The stabilizers of the red beads are unique in that they allow the distinction among beads excavated in other areas in South Korea owing to their compositional differences. Colorants in blue- and red-colored beads are cobalt (containing MnO), and copper and iron, respectively.

• Journal of Conservation Science
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• v.37 no.3
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• pp.232-244
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• 2021

This study examined the physical attributes and heat treatment characteristics of glass beads excavated from the Gimhae area, which is the location of Geumgwan Gaya. This enabled classification of surface characteristics of the beads based on the investigation of the color, size, and shape. The glass beads were classified into eight color systems, with purplish-blue beads as the representative color. Bead size was categorized into three types depending on the outer diameter and how it increased over time. Bead shapes were categorized as round, tubular, or doughnut-shaped based on the inner diameter and length, with round being the typical shape. According to the degree of heat treatment, there are three types of cross-section for glass beads that are manufactured by the drawing technique, most of which are the HT-III type. In addition, it is estimated that the heat treatment technology has more considerable effects than other methods. Through non-destructive analysis, the chemical composition was obtained and categorized as flux, stabilizer, and colorant. Analysis confirmed the presence of 63 and 9 pieces in the potash and soda glass groups, respectively. Overall findings from the study highlighted a correlation between the chemical composition and the external factors such as color, size, shape, and manufacturing technology of glass beads recovered from Geumgwan Gaya, revealing characteristics related to that time and region.