Definition of ruby glass in English:

ruby glass

noun

  • [mass noun] Glass coloured red by the inclusion of specific impurities such as gold or metal oxides.

    • ‘The art of incorporating this liquid gold into ruby glass is attributed to German glassmaker Johann Kunckel in the late seventeenth century.’
    • ‘Even before that, the island was shrouded in legend after alchemist Johannes Kunkel tried to make gold there in the 17th century, producing ruby glass instead.’
    • ‘Others were ambrotypes, a related antique method in which the original plate is backed with ruby glass or some other dark material that reverses the negative image.’