Origin of Material: AMIS0492 is a commissioned CRM made from material supplied by Geita Gold Mine, which is wholly owned and operated by Anglogold Ashanti. The Geita Gold Mine is situated 80km south-west of the town of Mwanza in the north-west of Tanzania. The Geita gold deposit is an Archaean mesothermal orebody, located in the Sukumaland Greenstones of the Geita Greenstone Belt. It is largely hosted in a banded ironstone formation (BIF). Mineralisation is found where auriferous fluids, which are interpreted to have moved along shears often on BIF-diorite contacts, reacted with the BIF. Some lower-grade mineralisation can occur in the diorite as well (usually in association with BIF-hosted mineralisation). Approximately 20% of the gold is hosted in the diorite.
Approximate Mineral and Chemical Composition: The major gangue mineral is magnetite with quartz, ankerite, and minor pyrrhotite and chalcopyrite. Gold occurs primarily as discrete grains
Au Pb Collection 4.00 ± 0.19 g/t