Purpurin (Italian: Porporino; Latin: Haematinum, derived from Greek haimátinos = "of blood"; German: Hämatinon), sometimes referred to as glass porphyr, is an opaque glass of brownish to lustrous deep-reddish color which in classical antiquity was used for residential luxury objects, mosaics and various decorative purposes. Purpurin is somewhat harder than normal glass but can be easily cut and polished. Its red color is permanently lost upon smelting. The material bears some resemblance to goldstone.