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EducationDevitrification of obsidian, transition to perlite
7th Apr 2024 06:51 UTCStefan M.
I'm curious regarding that subject. I know it is pretty much chemical weathering caused by contact with water. Is the process gradual, and if so, how do the various stages work? At what point would you consider something to be obsidian and something to be perlite?
Also, does tachylite turn to perlite?
7th Apr 2024 08:50 UTCDalibor Matýsek
I'm sorry, but the answer is definitely no. Perlite is not a devitrification product of obsidian. Devitrification is not chemical weathering, but the recrystallization of glass to a de facto high-temperature phases, corresponding to the normal components of igneous rocks.
Perlite is a separate type of glass that contains some water, but is still predominantly glass. Glass altered by chemical processes is usually called palagonite.
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