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.
|Verde Perola, Bahia Green, Lincoln, Verde Amazonia|
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||Granite – Charnockite|
|Age||1.2 Billion years (Precambrian)|
|Colouring minerals:||Dark green-olive feldspar, yellow-olive feldspar, blue-grey quartz, black biotite|
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||Brazil – near Ubatuba village|
A medium to coarse grained, olive-green granite (charnockite) of the Precambrian period with large quantities of quartz and some red garnets.
There are many different quarries supplying similar granites under many different names but all from the same region.
Petrology: Charnokite is a predominantly dark green plutonic rock similar to granite, the magma of which originates from the transition area between the earth’s crust and upper mantle. At the grain boundaries, gold brown to yellow olive coloured pigmentations can be found. The yellowish portions have been generated by metamorphosis of hypersthene minerals. Depending on lighting and viewing angle, the feldspar crystals, structured in zones, show slight light reflections. Quartz occurs in rather insignificant quantity in the form of small colourless or light blue-grey crystals.
Petrogenesis: During the Pre-Cambrian Period huge magma complexes surfaced from the transition zone between earth’s mantle and crust, forming granite or granite-like plutonic rocks. In the case of the Ubatuba massif, a pyroxene and ore-rich type of magma dominated, which settled below the earth crust and crystallised in stable cooling conditions. These deposits were uncovered during the millions of years by movements of the earth crust and erosion. Today they can be quarried directly below the vegetation cover.