Sand Mining Oyo State

201787gemstone mining gemstones like sapphire, ruby, aquamarine, emerald, tourmaline, topaz, garnet, amethyst, zircon and much more, are available in large quantities in nigeriaaraiba tourmalines found in oyo state, for instance, can sell for as high as 5,000 per karat, while a karat of ruby could sell for as high as 10,000, depending on the.