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.
|Nero Fossil, Galaxia, Galaxy, Morocco Black|
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.
|Petrographic assignment||Sedimentary limestone with orthoceras|
|Age||approximately 395-345 million years (Devonian)|
|Colouring minerals:||Calcite, coloured black by carbon-like substances and low bitumen contents|
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.
Petrology:A grey-black to black sludge, which is covered with orthoceras, the shells of fossil cuttlefish / squid. The shells are conical and have clearly visible chambers. The animal itself, of which obviously no residues are left, lived in the front part of the housing, while the empty chambers were used as ballasts with air and water. After the animal died these were filled with a small portion of sediment and the rest with crystalline lime spar. Such a large number of orthoceras are only found in this stone.
Petrogenesis:Lime spar is a sedimentary rock. In this case, it is a so called sludge limestone, the dark colour of which is caused by organic substances (bitumen). Such limestone is only generated on the sea bed in an oxygen-starved environment.