Zimbabwe Black Granite
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Synonyms: Absolute Black Zimbabwe, Black Zimbabwe, Negro Zimbabwe, Nero Assoluto Z, Nero Assoluto Zimbabwe, Nero Zimbabwe, Noir Zimbabwe, Zimbabwe, Zimbabwe Black, Zimbabwe-Black
Location: Zimbabwe Black granite is quarried at Mashonoland, Zimbabwe.
Description: Zimbabwe Black granite is a fine-grained, black gabbro/norite. This stone internationally may be nominated as a granite but in the area of application of the European Standard this stone must be nominated as a gabbro.
A small sample of Zimbabwe Black granite is usually representative not having a wide variation in colour and veining however swatch samples must be approved for large projects to ensure that the blocks are all extracted from the same quarry face for matching purposes. Ideal for both interior and exterior use, Zimbabwe Black granite is frost free and polish constant.
Technical and Physical Characteristics:
Compression tensile strength: 3011 kg/cm2
Tensile strength after freeze-thaw cycles: 2636 kg/cm2
Unitary modulus of bending tensile strength: 280 kg/cm2
Water imbibition coefficient: 0,000100
Impact strength: 69 cm
Mass by unit of volume: 2989 kg/m3
Gabbro: A dark-coloured, coarse-grained intrusive igneous rock. Gabbro is very similar to basalt in its mineral make up. It is composed mostly of the mineral plagioclase feldspar with smaller amounts of pyroxene and olivine.
Norite: A mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite and hypersthene with olivine. Norite is essentially indistinguishable from gabbro without thin section study under the petrographic microscope. The principal difference between norite and gabbro, however, is the type of pyroxene of which it is composed; norite is predominately composed of orthopyroxenes, largely high magnesian enstatites, whereas the principal pyroxenes in gabbro are clinopyroxenes, generally medially iron-rich augites.