The 1960's saw the discovery of many new gemstone varieties in East Africa. It seems likely that the most significant of these discoveries was the discovery of Tanzanite in 1967 by Portuguese prospector Manuel d'Souza in the Merelani Hills of Tanzania in 1967, in the shadow of majestic Mount Kilimanjaro. This breathtaking location is the only known mining site on earth for the exotic gemstone which would come to be named "tanzanite". Tanzanite is the velvety purplish-blue variety of the mineral species Zoisite. Its rich purples and blues often have a depth comparable to the finest sapphire.