Fenite

Fenite

 

a leucocratic metasomatic rock, a type of alkalic syenite. Fenites usually contain 70–90 percent alkali feldspar and 5–25 percent aegirine; alkali hornblende, sphene, and apatite are accessory minerals. Fenites sometimes contain calcite. Fenites are formed at the contacts of gneisses and granitoids with alkalic or carbonate intrusions. They may retain the banded texture of gneiss; in this case, biotite is completely replaced by alkali hornblende or aegirine. Fenites were described in the Fen area of Norway.

References in periodicals archive ?
6], first natural niobium-rich sulfide from the Khibina alkaline complex, Russian Far North: evidence for chalcophile behavior of Nb in a fenite.
NEW FIELD OBSERVATIONS ON PEGMATIC CARBONATITES, SILICQ-CARBONATITES, AND CARBONATITE-CEMENTED SODIC FENITE BRECCIAS AT OKORUSU, NAMIBIA.
However, we have also found zeolites in various granitic pegmatites, nepheline syenitic pegmatites, fractured diabase dikes, calc-silicate gneisses and fenites in the same area, and in agpaitic rocks and calc-silicate skarns in the CMBBZ.