The Sadba granite, 2 km southeast of Nakoalba, is oval in plan and 7x5 km; it cuts migmatites, granites and schists. The rock consists of perthite, quartz, riebeckite and in some facies euhedral aegirine; accessories are titanite, zircon, calcite, magnetite, fluorite and in some rocks biotite, while in two specimens a white mica was found by Ducellier (1963) who identified it as lepidolite. An analysis is available.
DUCELLIER, J. 1963. Contribution a l'étude des formations cristallines et métamorphiques du centre et du nord de la Haute-Volta. Mémoires du Bureau de Recherches Géologiques et Minières, Paris, 10: 1-320.