Allanite-(Ce) and epidotes in a feldspar deposit from Central Sardinia, Italy

Epidotes occur in albitites as light rare-earth element (LREE)-bearing accessory common phases.Chemical data suggest that there is a near complete solid-solution between epidote and allanite. In epidote-group minerals a pronounced zoning in REE was observed. The alteration epidotes mainly occur and generally originate from plagioclase alteration and from leaching of magmatic allanite. Comparison of textures using integrated SEM and EPMA techniques showed that the characteristic 'patchy zoning', observed in epidotes, corresponds to different amounts of REE in these minerals.