The Gazo mass is an eclogite−bearing tectonic block within the Sambagawa metamorphic belt，central Shikoku，Japan．Chemical compositions of constituent minerals in pelitic and basic schists and eclogites from the Gazo mass have been analyzed by EPMA．Garnets contain < 13 mol% of the pyrope molecule and < 35 mol% grossular Clinopyroxenes are aregirine-augite and omphacite．Amphiboles are both sodic-calcic（magnesiokatophorite，katophorite，magnesiotaramite，taramite and barroisite）and calcic（edenite，ferredenite and magnesiohornblende）．The white micas present are paragonite and phengite．