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Giallo Venezia

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

Very coarse crystalline granite, strong ochre to golden brown, which reminds somewhat on gneiss in its grains and structure (in part oblong oriented crystals). The main components form potash feldspar, up to 10 cm in size, partly shaped oblong or irregular. Included in between are smaller, light-grey transparent quartz crystals and oblong fibres from black biotite mica. The biotite can also be enclosed in feldspar in the shape of fine scales. Around the larger crystals from biotite mica are more intensely coloured brown areas, which fade towards the outside. These surrounding areas are typical for the appearance of tropical granite and they were generated over the millions of years by modification of the biotite iron content due to weathering into brown colouring mineral limonite. As accessories also deep red, up to 1.5 cm large, garnet crystals occur, which indicate that Giallo Venezia was partially exposed to metamorphous conditions. 

Petrogenesis

Over several millions of years, the magma complex of Giallo Venezia solidified very slowly in the earth's crust, whereby the large feldspar could form by collective crystallisation. Forming of mountain ranges pressed the rock massif into a greater depth into the area of the beginning metamorphosis. During this stadium, the dark red garnet crystals were generated. The following folding-up brought Giallo Venezia up to the earth's surface. The biotite iron content had been activated by physical weathering and changed into brown limonite (iron hydroxide). Depending on the intensity of this process, yellow or golden brown rock was generated.

Hardness Hard Stone
Structure Type Homogeneous Structure
Synonyms Amarello Veneziano, Juparana Venecia, Korall Gelb,Venetian Gold
Group Plutonic rock - Plutonite
Petrographic Assignment Granite
Age 1.2 billion years (Pre-Cambrian)
Colouring Minerals Beige to maize-yellow feldspar, grey-transparent quartz, black biotite, brown-red garnet
Average Hardness 6-7 (according to Mohs's hardness scale 1-10)
Deposit Brazil - in the Federal State of Espirito Santo, near the town of Nova Venecia