Was the Formula for True Black Glass Lost?
December 26, 2018 10:58 AM Subscribe
I read this tantalizing tidbit on wikipedia: "Formulas for different colors of glass are closely guarded. The recipe for a true black glass was lost during World War I, and modern black glass held to sunlight is a deep purple. Examples of true black glass are circulating in jewelry pieces made to commemorate the funeral of Queen Victoria." Unfortunately, it's totally unsourced, and my research hasn't turned up any extra information. Did true black glass ever exist? Do you know anything about the chemistry of glass?