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Location: Matrix granite is quarried in Minas Gerais, Brazil.
Description: Matrix granite is a banded and folded, dark grey biotite gneiss with big biotite clots. This stone internationally may be nominated as a granite but in the area of application of the European Standard this stone must be nominated as a gneiss.
The veining and colour varies considerably and a small sample of Matrix granite may not be representative of the whole slab therefore swatch samples must be approved for large projects to ensure that the blocks are all extracted from the same quarry face for matching purposes. Ideal for both interior and exterior use, Matrix granite is frost free and polish constant.
Technical and Physical Characteristics:
Compression tensile strength: 1993 kg/cm2
Tensile strength after freeze-thaw cycles: 1590 kg/cm2
Unitary modulus of bending tensile strength: 111 kg/cm2
Water imbibition coefficient: 0.002250
Mass by unit of volume: 2623 kg/m3
Gneiss: A common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks. Gneissic rocks are usually medium to coarse-foliated and largely recrystallized but do not carry large quantities of micas, chlorite or other platy minerals. Gneisses that are metamorphosed igneous rocks or their equivalent are termed granite gneisses, diorite gneisses, etc.