also: デーサイト
noun
dacite
A fine-grained volcanic rock intermediate in composition between andesite and rhyolite. Used in geology and petrology.
デイサイトは安山岩と流紋岩の中間的な組成を持つ火山岩です。
Dacite is a volcanic rock with a composition intermediate between andesite and rhyolite.
Borrowed from English 'dacite', which derives from Dacia, the ancient Roman province where the rock was first described.