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Description:
· Granites are coarse grain igneous rocks containing quartz,
feldspar and mica. They are formed in the slow cooling of molten material,
usually under great pressure, and are crystalline, hard and heavy.
· It should be noted that granite has a greater strength, has
less water absorption and in general is more resistant to staining,
than marble.
Characteristics:
Each granite has it's own characteristics when processed. eg
· Calca can have a slightly pitted polished surface.
· Emerald pearl can have fine lines around each of its crystals.
· All granites vary in colour from block to block, even within
their colour grades.
· Harcourt and Darwin Brown are subject to random black spots.
· Grandee is subject to occasional random black spots.
· The "grained/textured" imported granites, such
as Paradiso, vary in appearance in texture, graining & colour
from block to block and slab to slab, and are subject to small naturally
occurring cracks.
Finish:
Common finishes are as follows:
· Sawn - edge or back
· Buzzed/Dressed - edge or back
· Honed - edge or face
· Polished -face, edge or back
· Rustic/Rocked - edge or back
· Four pointed - used for decorative finish
· Sand blast - used for decorative or non slip finish
· Exfoliated - non slip or decorative finish
· Natural boulder
Life:
· Polished granite surface is highly resistant to weathering.
Maintenance:
· Polished surfaces easily wash with water & sponge/chamois
· Soap/detergent added for more stubborn contamination OR
use 6 drops of eucalyptus oil in ½ bucket of warm water.
· A soft nylon kitchen scourer can be used lightly if necessary,
but could dull the surface.
Note: Polished granite may scratch/mark with abrasive material.
Cuttlefish
backbone & water can be used to remove some contaminants.
· Unpolished surfaces may need high pressure water blasting.
· Mineral/Salt deposits from irrigation water may be
removed from polished surfaces with a carefully used flat razor blade
& then cuttlefish.
Preventive Maintenance:
Exterior applications:
· Polished granite memorials should be swept/dusted
before walking on as a twisting foot on coarse dirt/grit may cause
an abrasive action on the polished surface.
· Oil/grease should be soaked up quickly, not wiped/spread,
from a granite surface as it will penetrate the surface and leave
a stain. The residual stain can be partially dissipated into the granite
by soaking with a non oily solvent, ie Toluene, white spirits, methylated
spirits.
· Candle wax can penetrate & stain granite.(The
granite heats up by the sun and melts the wax into it's surface.) No
known treatment.
Interior applications:
· Granite used for Interior applications, where staining
could occur, can be sealed with a commercial sealer, ie KR33
· This should be repeated at regular intervals if in a high
risk area, ie Kitchen & bathroom bench tops. Light coloured granites
need more regular protection than dark ones.
Carrara:
Characteristics:
· Carrara is softer and more porous than granite.
· It is easily stained with naturally occurring contamination,
ie leaves, red dirt. etc
· Not recommended for painted or gold lettering.
Finish:
· Honed finish on face (eggshell finish).
· Sawn or dressed finish on other faces.
· Can be rusticed.
Life:
· Marble surface is subject to weathering over time, which
can affect lettering, appearance and strength.
Maintenance:
· Light cleaning with detergent/soapy water and a scrubbing
brush.
· Can be cleaned with high pressure water blasting, but some
staining may remain.
· Some stains can be reduced by bleaching with a domestic bleach
or diluted peroxide.
· Sometimes cleaned with acid, but can leave a yellow tinged
finish and can promote deterioration of the surface.
Mintaro:
Description:
· Slate is a natural layered sedimentary rock with cleavage
planes which are straight and parallel.
Characteristics:
· Slate is tough and resistant to wear and weathering.
· Susceptible to staining from oils etc.
Finish:
· Split face - has a uniform texture.
· Dressed
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