The summit of the Sabinyo volcano marks a triple international boundary junction between Congo, Rwanda and Uganda. About half of the products of the volcano lie in Rwanda and these are described under Rwanda No. 3. Approximately one quarter of the volcano lies in Uganda and contributed substantially to the Bufumbira field, information on which will be found under Uganda No. 8. Little work has been undertaken on the part of the volcano lying in Congo. It is important to note that the products of this volcano are the only ones in the Virunga volcanic field that are silica saturated and oversaturated.