Botsi

This occurrence consists of two bodies of nepheline and liebenerite syenite that cut through coarse- and medium-grained muscovitized syenites which grade into biotite syenites at depth – as indicated by drilling. The nepheline syenite bodies do not exceed 10 x 5 m and are composed mainly of alkali feldspar (40-50%), albite (5-20%), nepheline (2-50%), biotite (5-15%) and aegirine (5-20%). Accessory minerals are represented by titanite, zircon and apatite; overall they do not exceed 1-2%. The nepheline syenites vary from fine- to coarse-grained with pegmatitic varieties. The texture of the rocks may be gneiss-like or massive.