Where does stone come from?

Majority of the stones used to carve originates from the Eastern Highlands commonly know as ‘Nyanga serpentine’ or The Great Dyke, a volcanic ridge running for 1300 kilometres across the centre of the country in the direction south west to north east. It is the longest linear mass of volcanic rock in the world.  For millions of years heat and pressure concentrated on this ancient rock mass have created a unique mineral fusions, which can now be seen in all the different colours, shadings and combinations of hard and soft stones.

Sculptors in Zimbabwe carve a variety of stone from the hardest springstone to the softest of soapstone. The stone range includes verdite, many types of serpentine, opaline, dolomite, leopard rock, various steatite and soap stones. This gives the artists a large range of textures and colours to choose and work from. The stone colours are formed by trace elements and minerals included in the molten stone million of years ago. The main inclusions are chrome, copper and ruby corundum all form part of magic and mystique of this magnificent, exquisite contemporary art form. 

Serpentine and springstone are the stones preferred by the artists. They have a wide range of hardness and colour. The colour or combination of colours has left the artists with over 200 different colour stone variations from which to carve. Verdite an ancient brilliant green semi-precious stone is over 3.6 billion years old. Verdite can be an extremely hard stone as it may have areas where ruby corundum the second hardest stone on earth is included. Zimbabwean verdite commonly known as ruby verdite is unique to Zimbabwe because of these ruby corundum inclusions. The only other deposit of verdite is found in South Africa.

Majority of the time, the artists due to their ability to read the stone do not mark or draw on the stone surface but follow the stones natural form and contours when sculpting. The stone itself dictates to the artist the subject hidden within it. Once the hammering and chiselling is completed the artists then starts to smooth the nearly completed rough sculpture’s surface with various diamond studded and high carbon steel files to achieve a finer smoother finished surface. The next step, the sculpture is honed (polished) using various grades of wet/dry water paper. The last grade to be used being either a 1200 or a1500 grit. This will give a very fine smooth surface ready to absorb the final clear waxing process.  The sculpture is then placed near a fire (or similar artificial method of heating can be used) and heated before applying coats of beeswax or clear wax polish to draw out the colours of the stone. The sculpture is then left to cool down and only once the sculpture is cold can the final shining process be completed. Stone being a natural product will absorb wax readily.

Soapstone
Soapstone is a natural soft stone, with a ‘soapy’ texture when wet. Although somewhat soft, soap stone is a very dense stone, denser than marble, slate, limestone and even granite, making it naturally waterproof - liquid spilled onto the stone’s surface is not absorbed. Soap-stone is found on every continent and has been used by a countries native people for thousands of years – pieces of soap stone have been found in igloos in the Arctic, tombs of Pharaohs, Chinese and Indian palaces and the mountains and valleys of Africa.

Sapolite
An opaque milky-white serpentine, medium-hard stone (Moh rating 4) easy to carve and yet rarely used by artists.

Opalstone (Opaline)
A harder stone (4-5 on the Moh scale), Opalstone is known for its extremely close grain texture. The colour green is predominate, from milky light coloured green with orangey iron deposits, browns, fire-reds, blacks, sometimes mottled or specked with red, orange and bluish dots or patches. A favourite stone with carvers, Opalstone is not as hard as Springstone and some serpentines and can be rather brittle, will polished to a high gloss finish.

Springstone (black iron serpentine)
Springstone the hardest stone generally carved (5-6 on the Moh scale), Springstone a very fine grained hard stone that polishes to an amazing black lustrous finish that resembles black opal - not surprisingly it’s extremely fine finish and excellent durability is highly sought after. A regular feature if this black stone is to have a layer of chrome ore running through the sculpture. This vein of ore is extremely hard and during the polishing of the sculpture the softer stone adjacent to the vein wears away faster than the chrome vein leaving the vein standing out proud. A further feature of springstone is it maybe covered with a thick layer of reddish/brown material. This is the oxidization of the iron in the stone. Many of the artists use this additional feature of the stone to give a sculpture a two tone effect. This ferrous oxide is softer than the heart of the stone.

Leopard Rock

It is similar to serpentine; having a creamy yellow colour 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.

 Pyrophyllite
Pyrophyllite is commonly known as “Wonderstone”.  Is grey colour from deposits found in South Africa and mottled from deposits found in Namibia .Not many artists carve this medium.  It has a very fine grain construction and is measured between 2-3 on the moh scale.  The composition of the stone is compressed volcanic ash and is inert and is famous for not being a conductor of heat or electricity.
Ottosdal is the only place in South Africa where the unique “Wonderstone” pyrophyllite is mined.  The colour of the stone found there is grey.   Brandberg in Namibia is where this stone is found. The colour of the stone found there has a variety of colours due to mineral inclusions. It is extensively used in nuclear power stations and was used for making tiles for rockets re-entry shields so that rockets could re-enter into the earth atmosphere. Once this stone has been polished it has a beautiful high gloss finish and turns from grey to black with the application of wax.

Lepidolite
Lepidolite is a semi-precious stone with various shades of purple. It can be an extremely hard stone. Only skilled sculptors attempt to carve lepidolite. The stone is a quartz with lithium giving it it’s colour. It has been used as a source for the extraction of lithium.

Dolomite
Dolomite is often pink or a pinkish white but can also be white, grey or even brown or black depending on whether iron is present in the crystal.  Dolomite in it’s common form is made up of group of small rhombohedron crystals with curved saddle-like faces. Dolomite is a common sedimentary rock where Iron and Manganese deposits are sometimes present.

Ruby Verdite
Ruby Verdite is a relatively soft stone (rated 3-4 on the Moh scale) at certain places due to the ruby corundum inclusions it can be very hard. Corundum is the second hardest stone on earth behind a diamond; only the more experienced sculptor will attempt to carve this semi-precious stone. It has a unique mottled emerald green colour with brown and green striations, changing patterns with changing colours shades ranging from golden browns to rich emerald greens and blues.

Zimbabwe’s ruby verdite contains corundum and is a by-product of the extraction of the corundum mineral, corundum’s a member of the ruby family) and ruby verdite was declared a semi-precious stone by the British Geological Society back in about 1985 – so besides being beautiful it also has an intrinsic value and is becoming rarer, ruby verdite is only found in Zimbabwe where it is known as “Green Gold”. The only other known deposit of verdite in the world is found in South Africa and it does not contain corundum and therefore is not deemed to be a semi precious stone.