Yaramoko is underlain by geology considered to be similar to that of other Birimian-age volcano- sedimentary sequences. Hence, this region is considered prospective for orogenic gold deposits, which typically exhibit a strong relationship with regional arrays of major shear zones.

Gold is the main mineralization of economic interest found to date on the Yaramoko property. The main areas of gold mineralization are the 55 Zone, Bagassi South, 109, and 117 zones. The 55 Zone and the Bagassi South zones are the two main zones, both of which are hosted in the Diebougou granitoid domain.

The 55 Zone occurs in a reverse dextral shear zone and gold is primarily associated with quartz veining. The bulk of the gold mineralization occurs in dilatational segments of the shear zone where quartz veins are thicker and exhibit greater continuity. Gold typically occurs as coarse free grain in quartz and is associated with pyrite. The gold-bearing veins range from a few centimetres to more than 4 m in width, and have only minor contents of disseminated pyrite (frequently less than 1%). Adjacent sheared vein wall rock locally contains a small percentage of pyrite.

The Bagassi zone is an area of artisanal prospecting located south of 55 Zone that yielded positive geochemical results. At Bagassi South the mineralization consists of pyrite hosted in quartz veining. The surface definition of the vein can be traced by the artisanal mining. The vein is discontinuous over a strike length of some 800 m and is believed to dip to the southwest. Gold mineralization at Bagassi South is associated with quartz, white mica and pyrite alteration.

Four mineralogically distinct hydrothermal veins were defined: 1) quartz-rich veins, 2) iron- dolomite rich veins with quartz and muscovite, 3) iron-dolomite and quartz veins with albite, and 4) albite-rich veins with quartz and iron-dolomite (GeoMinEx, 2013). Native gold is present in each vein type, with accompanying sulphides mainly as pyrite and traces of tellurides. The most abundant sulphide mineral, pyrite, occurs in veins, altered wall rock. Textural and chemical complexity of pyrite document protracted period of crystallization from a compositionally evolving hydrothermal fluid. Native gold occurs in numerous textural associations and at a wide range in grain size ranging from less than 1 and up to 300 micrometres.

The second type of gold mineralization encountered is also associated with pyrite, occurring in zones of conspicuous shearing primarily in the volcanic rocks, with minimal to no significant quartz veining. These two styles of mineralization represent two end-members of brittle-ductile deformation within the 55 Zone where coarse gold in veining, usually seen in a granitic host, defines a more brittle environment while pyrite and shearing in the volcanic rocks is typical of a ductile domain.

Mining operations at Yaramoko are comprised of the 55 Zone underground mine, which was commissioned in 2016, and Bagassi South underground mine, which was commissioned in 2019. The underground operations utilize longhole stoping with cemented rock fill as its primary mining method. Mine development and stoping operations are conducted for Roxgold by African Underground Mining Services under a mining services agreement.

The processing plant was expanded in 2018 increasing the design capacity from 270,000 tonnes per annum to 400,000 tonnes per annum. The expansion was designed by DRA (Pty.) Ltd in Johannesburg, South Africa.

The processing plant uses the conventional gravity/CIL gold recovery processes. The comminution circuit of the process plant is comprised of a primary jaw crusher and secondary cone crusher – both in open circuit – followed by a SAG (Semi Autogenous Grinding) mill.

This is followed by a gravity circuit fed from the cyclone underflow stream, consisting of two centrifugal concentrators and an intensive leach reactor for treatment of the gravity concentrate, treating 70 percent of the cyclone underflow. The process also includes a carbon-in-leach (CIL) circuit consisting of one leach tank and five adsorption tanks, treating the cyclone overflow.

The metal recovery and refining circuit consists of an elution circuit, electrowinning cells, and
smelting furnace.