The colors of medieval stained glasses depend on their chemical composition. The redox interactions in glass between iron and copper and their influence on the color were investigated in two soda‐lime silicate model glasses. Both glasses have close iron and copper redox ratios and copper oxidizes iron when the iron content is smaller than the copper content. The redox speciation of iron and copper was determined using combining x‐ray and optical absorption spectroscopies in relation with the resulting color. The molar extinction coefficient of Cu²⁺ was estimated from the combined analysis to be 32 mol/L/cm. The glass color change from green to blue‐green color is assigned to the decrease of the total iron content, confirming that ancient glassmakers could control the final color with the glass recipe. These results provide reference data for further spectroscopic investigations of medieval stained glasses. Comparison with ancient copper‐colored green glass compositions suggests that the higher ratio of copper to iron total contents was imposed by the more reducing melting conditions in medieval furnaces.

中文翻译：

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通过模型的中世纪绿色眼镜看：从颜色到配方

中世纪彩色玻璃的颜色取决于其化学成分。在两个钠钙硅酸盐模型玻璃中研究了铁和铜之间玻璃中的氧化还原相互作用及其对颜色的影响。两种玻璃均具有接近的铁和铜的氧化还原比，并且当铁含量小于铜含量时，铜会氧化铁。铁和铜的氧化还原形态是通过将X射线光谱和光学吸收光谱结合所产生的颜色确定的。Cu ²⁺的摩尔消光系数从组合分析中得出的估计值为32 mol / L / cm。玻璃颜色从绿色变为蓝绿色的原因是总铁含量的降低，这证实了古代玻璃制造商可以通过玻璃配方来控制最终颜色。这些结果为中世纪彩色玻璃的进一步光谱研究提供了参考数据。与古铜色绿色玻璃成分的比较表明，铜与铁的总含量之比较高是由于中世纪熔炉中熔化条件的降低程度更大。