Porto Rose - Stone - Materials - Draenert
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Porto Rose

The close-up view of each stone type shows a relatively true image of the crystalline structure and the colouring. This is suitable for grained slabs to a limited extend only. In regard to the colour matching, please take an original sample of the stone from your furniture store as a basis.

Petrography

Jet-black migmatite with 30 % quartz, 45 % feldspar, 20 % biotite and 5 % muscovite content. The base crystalline, black from the high biotite content, is grown through by grey-white quartz veins and orange to red feldspar stria, which are responsible for the distinctive characteristics of this rock. Single fine scales of bright shining muscovite mica can be recognised on the surface. 

Petrogenesis

Two rock types have been mixed as original material in a migmatite rock, sediment rock and plutonic rock. Both were caught in a metamorphosis in connection with tectonic displacements and have been mixed by pressure and heat in a great depth and re-formed to a new rock. The characteristics are alternating of dark and lighter zones. The darker content (melanosome) stems from the sediment and is mostly enriched with a lot of biotite; the lighter content (leucosome) consists mainly of feldspar with red to yellowish colouring. In this case it is original magma. This stone group stands out by the lively and mostly colour-intensive markings.

Hardness Hard Stone
Structure Type Slab with Irregular Pattern
Synonyms Nero Porto Rosa
Group Metamorphite
Petrographic Assignment Gneiss - Migmatite
Age 600 million years (Pre-Cambrian)
Colouring Minerals White, transparent quartz, pink feldspar, black biotite
Average Hardness 7 (according to Mohs's hardness scale 1-10)
Deposit Brazil, Espirito Santo, Minas Gerais