The majority of stones used in Zimbabwean sculpture are locally sourced and belong to the geological family of Serpentine. They are sedimentary, having originally been laid down on a sandy sea floor and metamorphic, since subsequent exposure to intense heat and pressure over hundreds of millions of years has transformed them into hard stone. Serpentines are rich in iron, so when the stone weathers it turns a rust colour.
Zimbabwe houses The Great Dyke -a 2.5 billion year old horse-shoe ridge of 500km stretching through the North and East round to the centre of the country and is rich in minerals of every description.
Different areas of The Dyke produce a different variety of stone. Over 200 colours of stone have been geologically catalogued, ranging in
Mohs scale of mineral hardness from 1-5.5 on the scale of hard stones, with Granite being 6.
Serious sculptors prefer the hardest varieties such as Springstone. Dense stones have extremely fine grains and uniform structure, making them ideal raw materials for sculpting.
Most of the stones artists use are mined from this Dyke, by hand. Mines tend to be small-scale, open cast operations. They are too small to cause any environmental damage and form a valuable alternative source of income to rural communities.
Aquaprase
Recently discovered in 2013, aquaprase is fairly new to the gemstone tribe. This unique stone is a chalcedony quartz characterized by a blended mixture of a blue and green colour which is naturally caused by chromium and nickel. The stone is hard in texture and exhibits uniquely traced patterns throughout the gem.
Butterjade
Butter Jade has a creamy yellow colour with dark striations throughout and is sometimes also known as Butterstone. 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 Mohs hardness scale.
Cobalt Stone
A beautiful stone that is often purple with a variation of yellow and white markings and stripes throughout. Can often have brown/orange markings. 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 Mohs scale.
Dolomite
PHYSICAL CHARACTERISTICS: Colour is often pink or pinkish and can be colourless, white, yellow, gray or even brown or black when iron is present in the crystal. Luster is pearly to vitreous to dull. Transparency crystals are transparent to translucent. Hardness is 3.5-4 Streak is white. Associated Minerals: include calcite, sulfide ore minerals, fluorite, barite, quartz and occasionally with gold.
Lapidolite
A beautiful stone that is purple, this stone is absolutely stunning, especially in natural daylight. The colour can vary and is either dark purple or light, a colour you probably couldn’t even replicate!
Leopard Rock
A beautifully coloured stone with pock marks similar to a leopard, hence the name, of yellow and black. These are inclusions of the ferromagnesian mineral, olivine. Leopard Rock is an olivine rich serpentine (known geologically as dunite) which forms part of a serpentine complex 2.6 billion years old.
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3). Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera. Limestone makes up about 10% of the total volume of all sedimentary rocks. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. Limestone has numerous uses: as a building material, as aggregate for the base of roads, as white pigment or filler in products such as toothpaste or paints, and as a chemical feedstock. The first geologist to distinguish limestone from dolomite was Belsazar Hacquet in 1778.
Opal Stone
A beautiful light greenish serpentine. Opal stone is a very hard stone finely textured with an almost translucent surface sometimes specked with red, orange and bluish dots and patches. Opalstone is famous for its milky light coloured greens and smooth texture. It is also unique in that it has fewer colour variations than Serpentine. It is also mined at Chiweshe, two hours north of Harare. This stone is one of the favourites of sculptors, as it’s not as hard as springstone and other serpentines, but still polishes to a high finish. Opalstone also has, at times, a brown colour throughout the predominate green. The appearance can be smooth or mottled. As with most of the stones mined for the purpose of sculpting, opal is mined without the use of automotive tools. Lemon Opalstone is easily identified by contrasting yellow striations within the stone. On the Mohs hardness scale, Opalstone rates between 5.0-5.5.
Opal Stone (Golden)
Found in Domboshawa, Zimbabwe, a fairly hard stone, best to keep indoors as it marks easily.
Opal Stone (Lemon)
Usually a much deeper colouration all over the stone, more colourful and a harder stone to sculpt than the usual Opal Stone, mostly due to the particles of quartz found within the stone. Lemon Opalstone is easily identified by contrasting yellow striations within the stone. On the Mohs hardness scale, Opalstone rates between 5.0-5.5.
Red Jasper
Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue.
Rose Quartz
Red Quartz, sometimes referred to as Hematoid Quartz, is a variety of Quartz with a Hematite coating.
Serpentine
Found in many deposits throughout Zimbabwe its colours vary from black to brown to green, orange and variegated. Hardness level varies from very soft to vary hard. Measured on a moss scale where a diamond is ten, serpentine goes from 1.2 up to 6.54. The majority of the sculptors today, however do not carve from soft serpentine, but rather select deposits of rock that are hard and therefore more durable. Black Iron Serpentine derives its name from the deposits of iron found in it and is one of the hardest and darkest stones found in Zimbabwe. It has the most amazing black lustress finish that resembles the black opal and is highly sought after because of its fine finish, durability and hardness.
Serpentine (Fruit)
Fruit Serpentine is usually a really colourful pretty stone, with deep veins of variated strata. Serpentine is the next hardest stone with a rating of 4.0-5.0 on Mohs hardness scale. Because of it’s beauty and collectability it is one of the most sought after because of it’s fine finish, durability and hardness.
Springstone
A very hard serpentine with high iron content and a fine texture, no cleavages, hard and firm offering a good resistance to the sculptor. Springstone has a rich outer “blanket” of reddish brown oxidised rock. They emerge from the quarry like sculptures created by nature millions of years ago and are often a source of inspiration to the artist. There are a few mines where this stone is found, but Guruve, in the north, is where springstone is mined. A beautiful dark stone, it polishes to a high shine because of its density. As with most other stones that are mined for the purpose of sculpting, this stone is mined by hand on communal lands.
Verdite
An extremely hard stone, usually used in ‘Fine Art’ such as Elephants, Rhinos etc. Verdite is the term referred for a Fuchsite based rock discovered in South Africa. Fuchsite is an ordinary phyllosilicate stone, which belongs to the Mica group that are usually multifaceted hydrous potassium-aluminium silicate stones. It is also a chromium rich type of Muscovite, which provides its rich green shade with a spotless shine from the small crystals. Verdite also consists of a minor Albite, Chlorite and Corundum Group, Quartz, Diaspore, Rutile, Margarite, and Talc minerals. Moreover, it is related with Serpentine from the eastern part of Zimbabwe and South Africa. These Serpentine groups compared with the most common occurring. It used to get and achieve information from the earliest ones, amplifies ones strength and fidelity, facilitates to fight the harsh character attributes, and increases the energy, which centralizes the first four Chakras as well as, motivates the Kundalini for such areas. Colours: Glow to shady green, blue, yellow, and red. Sources: Verdite is restricted into specific regions, first in eastern Zimbabwe, and secondly in South Africa. Other Features: Verdite has an exclusive emerald looking value with green and brown striations and it is well-known as “green gold” because it is a semi-precious gemstone that is unluckily becoming unusual and therefore, gradually more priceless. It is a solid stone where more skilled sculptor will urge to carve it.