鉛ガラス(なまりがらす)namari garasu
成分に酸化鉛を含むガラス。光沢があり、加工性にも優れている。金属鉛(Pb)を加熱酸化して得られた鉛丹(えんたん)(Pb3O4)に、石英(せきえい)を加えて生成すると、一酸化鉛(PbO)と二酸化ケイ素(SiO2)からなる鉛ガラスができる。このとき不純物が混じらなければ無色透明となり、少量の銅を加えれば緑色に、鉄を加えれば黄色に着色される。
第76回 正倉院展、2024年
Leaded glass
Glass containing lead oxide is very shiny and easy to shape. When lead (Pb) is heated and sand added to the lead oxide (Pb3O4), lead glass can be made from the resulting PbO and SiO2. If no impurities are mixed in, this produces a colorless transparent glass, but if a small amount of copper is added, the color becomes green, while a small amount of iron makes it yellow. The Repository has not only leaded glass fish and beads, but also yellowish-red lead pigment used to color glass.
57th Annual Exhibition of Shōsō-in Treasures, 2005