Confusion around the term "turquoise" is rampant. African "turquoise" is actually a trade name, and the stone is jasper, not turquoise. However, the jasper really is found in Africa. African "turquoise" has a dark matrix and an interesting blend of base colors, a little greener than most turquoise. It can be dyed to achieve the turquoise-like color.
It is a beautiful stone to make jewelry with, but if you sell your jewelry pieces you should let your customers know that it's not turquoise.
SmartBeadShopping™ Tip: One advantage of African jasper is that it is harder than turquoise.