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.
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||Gneiss – Paragneiss|
|Age||700 million years (Pre-Cambrian)|
|Colouring minerals:||White feldspar, grey-transparent quartz, black biotite, silvery muscovite, spots of brownish pyrite (haematite)|
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-grained, grey to white-grey gneiss (paragneiss) of the Precambrian period with cloudy decoration, partly with pyrite and hematite.
The veining and colour varies considerably and a small sample may not be representative of the whole slab.
Petrology:Bright grey and white crystal paragneiss with an irregular cloudy pattern. Mainly composed of white feldspar and transparent quartz; black biotite streaks, some silvery muscovite and greenish epidote give the ornamentation. Clouds, folds and waves feature throughout.
Petrogenesis:Paragneiss; generated through metamorphosis of former sediment rock as a result of tectonic activities between the earth’s crust and mantle. There it re-crystallised, the mica minerals have been generated from the clay elements of former sediments.