Definition of "unvitrified" []

• Not converted into glass. (adjective)

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• "For some distance from the furnace, this flue may be made of brick or unvitrified sewer pipe, but stove-pipe may be used for the greater part of the run."
• "I consider even the pearlstone as an unvitrified obsidian: for among the minerals in the"
• "I consider even the pearlstone as an unvitrified obsidian: for among the minerals in the King's cabinet at Berlin there are volcanic glasses from Lipari, in which we see striated crystalites, of a pearl-grey colour, and of an earthy appearance, forming gradual approaches to a granular lithoid lava, like the pearlstone of Cinapecuaro, in Mexico."