Assessment of sand and stone mining along the coastline of Cape .However, these activities come at a cost to the coastal environment and pose a threat to the tourism industry along the Ghanaian coast. This paper identified the various types of coastal sand and stone mining activities, the level at which they are undertaken and covers the trends in coastal erosion along the coast of Cape.types of stones being mine in ghana,types of stones being mine in ghana,Gemstones from Africa - Gem Rock AuctionsJun 14, 2013 . While most people will know that Africa is the major source of diamonds, the colored gemstone trade is gradually becoming more significant. Although . Colored stones coming from the African mines are constantly changing with ew gems begin discovered every other week. Buyers have been educated to.