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.
|Black Amethyst, Nero Ametista, Black and Gold, Star Galaxy, Black Galaxy, Nero Galaxy|
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:||black pyroxene, bronze-colour broncite crystals|
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.
A fine to medium-grained, black gabbro with golden-yellow sparkling broncite scales.
Petrology: Gabbro: a dark, coarse-grained, intrusive igneous rock chemically equivalent to basalt. It is a plutonic rock, formed when molten magma is trapped beneath the Earth’s surface and cools into a crystalline mass.
The rock is a medium-grained, full-crystalline, regular stone consisting entirely of black pyroxenes (metal bearing silicate minerals) and of bronzite crystals of up to 1cm in size, uniformly distributed throughout the rock. Exceptionally, there may be a magnetite ore present. Bronzite is a silicate mineral with a bronze-hued shimmer which is often encountered in gabbroid rock.
Petrogenesis: Star Galaxy is a magmatite rock which is described as pyroxenite because of its mineralogical make up. A silicate-rich magma solidified beneath the primeval earth crust under highly stable cooling conditions. The result was the homogeneous graining of this recently discovered stone.