There are a variety of stones used for carving in Zimbabwe including lepidolite, butter jade, cobalt stone, leopard rock, opal stone, lemon opal, sapolite, serpentine, springstone, fruitstone, and verdite. The following link will provide you with images, descriptions, history and uses of the different stones: Stones of Africa.
We purchased a statue of a traditional Zimbabwe woman carved from "Butter Jade". Butter Jade has a creamy yellow color with dark striations throughout and is sometimes also known as Butter stone, as well as African--a stone called Stromatolite. Although it is called 'Jade', it is not, however, a true Jade. The striations found in the attractive yellow-green sedimentary rock are actually layers containing fossilized algae. The stone is typically around 50 million years old and between 6 and 7 on Moh's hardness scale.
Although you will see stone carvings in the open air markets I would suggest that you go to a store that is not in the open markets. We found a lovely store that only sold carvings from the well known stones of Africa, most particularly Zimbabwe. Many of them were signed, as well. We really liked two of the carvings--the one we purchased and one carved from Leopard Stone AKA Leopard Rock. Leopard Rock is a beautifully colored stone with spock marks similar to a leopard. It is similar to serpentine; having a creamy yellow color with black blotches. The only known deposit of Leopard Rock is in Zimbabwe. It is very difficult stone to carve. Only skilled sculptors will attempt this rock. Leopard Rock, when polished, has a beautiful glazed finish. Sometimes containing petrified wood. Unfortunately we only had enough room for one sculpture in our suitcase. The owner of the store did lower our price which was totally unexpected by us. He also gave us smaller US dollars for our change which we appreciated. We did not pay by credit card. I suspect that is why he lowered the price.