NEW Gallery on our new website
We have a new multi-language website dedicated to Granite Worktops at www.4graniteworktops.co.uk
This includes a new photo gallery and a visitors book for our customers to comment on our work.
If you can't find the stone you want, no problem, we can get almost every stone available.
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Granite Types
Baltic Brown
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Baltic Brown
Description of colouring and granulometry: granite characterized by a very peculiar petrographic structure called rapakiwi with a very coarse to coarse grain; it has a streaked and variable appearance with numerous feldspar orthoclase crystals of an oval or round shape and a brown or pinkish-brown colour, surrounded by thin borders of feldspare oligoclase. The interstices between the spherical aggregates contain fine-grained masses of black biotite, grey quartz and dark green hornblende. Biotite is also present in the form of small scales in the feldspar crystals. For this reasonthe appearance of this rock has strong contrasts. The high cost of this stone is due to the great difficulty in finding valuable stone that, besides being available in large quantities, does not undergo significant variations in quality over time. It is quarried in Finland, in the large granite mass forming part of the Finnish-Scandinavian crystalline shield, south of Lappeenranta, near the border with Russia, in the Lahnajarvi and Hujakkala districts of the Ylamaa region. Other commercial names: Baltic Brown, Rapakiwi Brown, Baltico Marrone. Prevailing applications: interior and exterior – wall cladding, flooring, slabworks and monumental art. Finitions-textures: polish. Mineralogical composition (weight %): potash feldspar 55, quartz 25, plagioclase 11, biotite 4 and horneblende 5. Physical and mechanical properties: volumetric weight: 2679-2690 kg/m3; porosity: 0.44%; water absorption: 0.14-0.16 (weight %); compressive strength: 148.1-170.8 MPa; mechanical bending strength: 4.9-11.9 MPa; thermal expansion: 0.5-0.9 mm/mx100°C; abbrasion resistance:54.68; breaking modulus: 10.73-13.8 MPa; wear for abrasion according to Boehme: 5-8 cm3/50cm2; Mohs hardness: 6. -------------------- Description from TRE Collection: materials, manufacturing and uses ANNUAL STONE by Beatrice Zoppas |
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