ABOUT THE STONES
Cobalt is a brittle, relatively rare hard metal, closely resembling iron and nickel in appearance. It has a hardness of between 5 and 6 on Mohn´s scale.
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 its 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.
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.
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 its color. It has been used as a source for the extraction of lithium.
A harder stone (4-5 on the Moh’s scale), Opalstone is known for its extremely close grain texture. The color green is predominate, from milky light colored green with orangey iron deposits, browns, fire-reds, blacks, sometimes mottled or specked with red, orange and bluish dots or patches. A favorite stone with carvers, Opalstone is not as hard as Springstone and some serpentines and can be rather brittle, will be polished to a high gloss finish.
Pyrophyllite is commonly known as ´´Wonderstone´´. It is grey in color 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’s 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 color of the stone found there is grey. Brandberg in Namibia is where this stone is found. The color of the stone found there has a variety of colors 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.
Ruby Verdite is a relatively soft stone (rated 3-4 on the Moh’s 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 color with brown and green striations, changing patterns with changing colors 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 is 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.
Many of the patterns and colors seen in these rock deposits throughout Zimbabwe are similar to those seen in some snake skins, which is why the term “serpentine” has come to be used to describe them. There are no scientific categories that perfectly match the names and meanings that sculptors use, but springstone, opalstone, leopard rock, lepidolite, cobolt and golden serpentine are all names that varieties (there are more than 200 of them) of this stone are given. The colors range from brown to black to green, and are sometimes variegated. Serpentine stone is 2.6 billion years old.
Soapstone is a natural soft stone, with a ´´soapy´´ texture when wet. Although somewhat soft, soapstone 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. Soapstone is found on every continent and has been used by countries native people for thousands of years, pieces of soapstone have been found in igloos in the Arctic, tombs of Pharaohs, Chinese and Indian palaces and the mountains and valleys of Africa.
Springstone, the hardest stone generally carved (5-6 on the Moh’s scale), is a very fine grained hard stone that polishes to an amazing very dark brown or black lustrous finish – 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 may be 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.
Verdite an exotic and wonderful stone of rare quality. It captures the mysterious and beautiful colors of an age-old area of Africa. Like the ever-changing sea, it is infinite in its variety of lovely shades and patterns, usually in green with inclusions of blues, gold, red and browns. Verdite occurs amongst the oldest rock in the world dating back over 3500 million years. The only known deposits are found in areas where gold was first discovered in Africa many centuries ago. The material has no cleavage and is riddled with intrusions of corundum (ruby) crystals (hence the name Ruby Verdite), quarts, calcite and mica. Chromium is the mineral, which gives Verdite its distinctive rich green color – Ruby Verdite can be extremely hard, corundum is the second hardest stone on earth.