Main Entry: ar·kose

Pronunciation: \ˈär-ˌkōs, -ˌkōz\

Function: noun

Etymology: French

Date: 1839

: a sandstone characterized by feldspar fragments that is derived from granite or gneiss which has disintegrated rapidly

— ar·ko·sic \(ˌ)är-ˈkō-sik, -zik\ adjective