Donnayite-(Y) from the Albyn gold deposit, Russian Far East

Abstract

515 The rare hydrous Y, Sr, Ca, and Na carbonate don� nayite�(Y) (Sr, Ba) 3(Y,Ca,Na)3[CO3]6 ⋅ 3H2O was first found in a pegmatite dike cutting across syenite of the Mont St.�Hilaire Massif in Quebec, Canada [1]. Until recently the mineral was known to occur only in rocks of alkaline complexes: along with St.�Hilaire, these were the Khibina Massif in the Kola Peninsula and the Vishnevye Gory Massif in the Urals [2, 3]; the mineral was also found in carbonatite in the Khibina and Vuor� ijarvi massifs in the Kola Peninsula [4, 5]. In derivatives of alkaline rocks, donnayite�(Y) is contained together with microcline, calcite, natrolite, aegirine, and more rare Sr, Ba, and REE carbonates. Donnayite is occasionally accompanied by albite, fluo� rite, barite, minerals of the labuntsovite group, and its Ba analogue mackelveyite.