Stones can have many aliases. This is due to language differences, supplier choice, coloquial trends or slang, or sometimes errors and ambiguity between rocks. Read more here.
|Jasberg, Impala Nero, African Impala, Rustemberg, Rustenberg, Rustenburg|
Commercial classification sometimes differs to the scientific, geological designation. In particular, some limestones are deemed marble especially if they take a high polish. Read more here.
|Age||1.4 billion years (Precambrian)|
|Colouring minerals:||Light-grey feldspar, black pyroxene, black-metallic shining ore minerals|
MOHS is the standard scale of hardness for minerals 1-10, with 10 being the MOHS of diamond. We also use the broad terms Hard and Soft for simplicity. Read more here.
|Origin||South Africa – near Rustenberg|
A dark grey gabbro/norite of the Precambrian period.
Homogeneous structure of black and grey graining.
Petrology: Impala has a homogeneous structure with an average grain size ranging from 0.5 to 1 cm. It consists of bright grey plagioclase feldspar, black to grey-black pyroxene and black-metallic shiny ore. The various mixture constituents are distributed in even concentration throughout the rock, so that a uniform grey-black colouring results. The light-grey feldspar, as well as the black pyroxene sometimes occurs in nest-shape. The possibly rough surface is created by short-term heating of the stone surface and transformation of the upper crystal layer into slate-like structure.
Petrogenesis: Norite belongs to the plutonic rocks of the dark, basic magma type. A metal containing melt of the upper earth mantle solidified beneath the Precambrian earth crust in homogenous cooling conditions extending over million of years. The homogeneity in the grain structure and structure is the result of this process and the extremely good technical characteristics of this hard rock result from this.