- 期刊
古銅錢的孔雀石拉曼光譜特性
Characteristics of the Raman Spectra of Archaic Malachites
摘要
古器物（考古）孔雀石，代表中國及越南古銅錢上的孔雀石礦物，也包含其他古器物上的孔雀石。本研究以氬雷射進行拉曼光譜研究，顯示其拉曼光譜與由現今礦山產出的自然孔雀石的光譜有些微差異。本研究進行40個古錢120個古器物孔雀石的分析，鑑定出26個拉曼振動模，其中的18個振動模較常出現。此18個振動模位置的波數（cm^(-1)）、偏移量（±）及強度分別為：153±4（0-vs）,179±7（m-vs）,217±8（m-vs）,274±7（0-vs）,355±5（0-m）,431±4（0-vs）,514±3（0-m）,533±5（0-s）,566±3（0-m）,599±2（0-m）,718±6（0-m）,754±2（0-m）,1,061±7（0-m）,1,093±10（0-m）,1,365±9（0-m）,1491±7（0-vs）,3,321±11（0-vs）and3,380±7（0-vs）。與來自五座礦山產出的自然孔雀石量測的105組數據相比，古器物孔雀石的拉曼光譜的振動模數目較少、背景值較高、並且具有較大的波數偏移量。振動模的減弱或消失程度依序為OH-拉伸（3,300cm^(-1)）（較為嚴重），CO_3（600~1,500cm^(-1)）以及CuO（＜600cm^(-1)）（較不明顯），顯示可能有埋藏環境之風化侵蝕。來自3個不同氣候帶的古銅錢上生長的孔雀石亦分別顯示出其拉曼光譜特色。有幾個古錢孔雀石展現的與礦山自然孔雀石不同且複雜的拉曼光譜，可能代表其經歷不同氣候環境之保存度影響。
並列摘要
Archaic malachites, represented by the malachites found on the ancient Chinese and Vietnamese copper/bronze coins, may also incorporate those on other archaeological objects. The Raman spectra with Ar laser of these malachites differ slightly from those of the natural malachites found in mines. In this study, 120 measurements of the malachites on 40 coins identified 26 bands, while only around 18 of them are frequently observed. The wavenumbers (cm^(-1)), shifts (±) and relative intensities (in parentheses) of the 18 common bands read respectively: 153±4 (0-vs), 179±7 (m-vs), 217±8 (m-vs), 274±7 (0-vs), 355±5 (0-m), 431±4 (0-vs), 514±3 (0-m), 533±5 (0-s), 566±3 (0-m), 599±2 (0-m), 718±6 (0-m), 754±2 (0-m), 1,061±7 (0-m), 1,093±10 (0-m), 1,365±9 (0-m), 1491±7 (0-vs), 3,321±11 (0-vs) and 3,380±7 (0-vs). In comparison with those of the 105 measurements on the natural malachites in five mines, the Raman spectra of the archaic malachites tend to show less bands, higher backgrounds, and greater shifts in the wavenumber position. The weakening or loss of bands is in the order of the OH stretch (3,300 cm^(-1)) (most severe), CO_3 (600-1,500 cm^(-1)) and CuO (＜600 cm^(-1)) (less severe) groups, indicating successive stages of corrosion. The malachites on the coins from three climate zones show their own characteristics. Several coins may have experienced two or more climatic or geologic episodes and show complex Raman spectra different from those of the natural malachites.