Nero Zimbabwe is not exactly a granite. Scientists have classified this material as a gabbro.
In 1810 the German geologist Leopold von Buch named this intrusive rock after the hills of Gabbro on the Tyrrhenian coast in the South of Livorno. Let us talk about the differences and the similarities between gabbro and granite.
Both are intrusive igneous rocks of volcanic origin, formed after the cooling process inside the terrestrial crust.
Granite and gabbro have a different percentage of silica (minerals mostly composed by silica and oxide), for the presence of other chemical elements their colour and resistance are different, too. Gabbro contains between 45% and 52% of silica (basic rock) whereas granite contains 63% and more (acid rock).
Granite is an acid rock with more than 63% of silica, its colour varies from white to red. The medium – medium fine grained gabbro contains translucent and colourless quartz, potassic feldspar (orthoclase), spare plagioclase and biotite (black mica). Sometimes it also contains muscovite (if there are granites with two micas), apatite, zircon, pyrite.
Gabbro is a basic rock, very dark, with plagioclase, pyroxene, amphibole.
What do these differences mean?
All these materials are generally (we noticed that during finishing process) very dark, that means the darker they are, the harder they are. Especially Nero Zimbabwe is a very solid and homogeneous stone, a basically black coloured gabbro with little dark grey coloured crystals.
As an example lets compare the minimum values of some resistance proof between a light granite, as Bianco Cristal, and a dark one, as Nero Zimbawe, according to the CE marking data.
|NERO ZIMBABWE||BIANCO CRISTAL|
|Resistenza a flessione||30,2 MPa||15,8 MPa|
|Resistenza a compressione||261 MPa||144 MPa|
|Carico di rottura in corrispondenza dei punti di fissaggio||2950 N||2450 N|
These values are very different and entirely to the benefit of Nero Zimbabwe, even though Bianco Cristal is a granite stone with high values of resistance compared to a marble stone.
Nero Zimbabwe can be applied in various forms as for its intense chromatic tonality, as for its hardness. This material is suitable not only for internal use but also for outside. The dark coloured Nero Zimbabwe is also appropriate for large dimensions: building panelling, panelling of hotel halls, flooring of large surfaces. Thanks to its great elegance it can be used for internal flooring and panelling, bathrooms, kitchen tops, etc.
In our opinion the best finishing to highlight the chromatic character and the aesthetics basically consists in polishing, the whole range of flaming brushing and Ecoantik (look at the photo above). The last two finishing methods are particularly suitable for outside or for wall panelling.
Have a look about Nero Zimbabwe sheet.