Introduction.

Tanzania has a wide potential of rocks that can be extracted as dimension and cut include granite, gneisses, marbles, travertine and anyolite

Granites.

Potential granite deposits occur in the Tanzanian Craton and in the Ubendian Super group in southwestern Tanzania. They occur in the regions of Dodoma, Mbeya, Morogoro, Mwanza, Singida and Tabora (Kanza, 1999). The granites occur in a variety of colours including pink, grey and black. They are generally fine to coarse grained.

• Outcrop of Nakapanya Granite, Masasi(Photo by P.Semkiwa)
• Scanned Image of polished black granite.

Marbles.

 Potential marble occurrences for prospecting, including white, blue, whitish grey, grey and pink-cream with green sports, occur in the eastern part of the country, that is in Bagamoyo, Handeni, Matombo-Uluguru Mountains, Kiborian-Uluguru Mountains, Mahenge plateau, Kihumbi-Igawa and Tanga areas (Mbasha, 1995). The rocks are also located in the northwestern part of the country in the Arusha and Kilimanjaro (Hai and Rombo Districts) regions.

Travertine.

 Travertine containing calcareous onyx occurs at Songwe Valley in Quaternary volcanic deposits of Rungwe. Resources are known to be in the order of 72million tonnes. The rocks can be cut into sizeable blocks. The deposit has been mined since 1991 by Consolidated Mines (T) and Natural stone Products process the material at Mbeya town

Appinite.

Appinite is a dark coloured hornblende-rich plutonic rock that is located west of Iringa town and in the Uluguru Mountains.

Anyolite.

Anyolite is another rock type suitable for exploitation for dimension and cut or art stones. The rock consists essentially of amphibole chromiferous zoisite and ruby corundum and is exposed in Merkenstein-Longido, north of Arusha and Dudumera near Babati.

• Pink granite outcrop at Singida(Photo by P.Semkiwa)
• Scanned Image of polished pink granite.

Quartzite.

Quartzite is found in the Chipogolo and Mafurungu/Simbanguru areas in the Dodoma Region, Kilosa in the Morogoro Region and Kinyangiri are in the Singida Region.

Basalt and Phonolite.

Basalt, phonolite and other volcanic rocks are widespread in the Arusha and Kilimanjaro regions northeastern Tanzania and in the Rungwe volcanic in the southwestern part of the country.

Slate and Flagstone.

Slate and flagstone are developed in the Musoma, Sumbawanga and Kigoma Districts and Chimala area near Mbeya town.

Outcrop of grey granite. Common in central regions of Tanzania.(Photo by P.Semkiwa)