STONECARE TECHNIQUES
RESTORATION v PRESERVATION

GRANITE

Granite is endowed with a unique elegance. Throughout the centuries this stone has
excited admiration for its beauty and time defying characteristics. Granite is a noble stone.

GROUP

Igneous

COMMON
R
OCK-FORMING MINERAL GROUP

Siliceous

COMPOSITION

Feldspar, quartz, and small amounts mica are the primary minerals of the average granite with minor accessory minerals.

HARDNESS

Hard      MOHS' SCALE 5 - 7

POROSITY %

0.4 - 1.5    ABSORPTION % 0.2 - 0.5

WEATHERING
C
HARACTERISTICS

Generally good to excellent. However, like any other material it has its vulnerable points...Some varieties contain ferrous mineral compounds that when continuously exposed to moisture, such as in marine coastal environments, will undergo mineralogical changes and being to produce discoloration's (rust spots)...In exterior applications, depending on the environmental conditions and the finish, darker granites, those with red and black minerals, have a tendency to fade somewhat

TENDENCIES

Absorbs oils and some will absorb other liquids...Generally not affected by acidic foods and drinks, however, polished granites can be etched by hydrofluoric acid and concentrated acids which are found in some household cleaning products...Some granite varieties when used in water features (spas and fountains), will begin to show signs of deterioration in a few years.

COLORS

Granite is found in more than a hundred distinct colors with varying patterns

FINISHES

Polished...Honed...Textured

NOTATIONS

When granite is used in the kitchen and bathroom it is highly recommended to treat the stone with a oil repellent...The grain size varies with this stone, from small, medium to coarse. This is important to understand for two reasons...1. With larger mineral grains or a combination of different grain sizes, the stone has a tendency to be more absorbent...2. Some varieties are composed with a combination of different grain sizes. This natural characteristic is  more noticeable in highly polished finishes. The surface of the stone may appear to have  tiny random pitting and a question that is often asked," is the finish of this granite defective in some way", and the answer is usually no. A real tight finish is not completely attainable with some of these varieties of granites. This characteristic is often not detected by viewing small samples of the stone...With textured exterior installations it is advisable to treat the stone with a water and soil repellent. Many of the texturing processes create and expose micro fractures in the stones surface increasing the absorption factor of the stone.
      * Contrary to popular opinion granite will stain.

True geological granite has been formed from molten material i.e. magma that cooled
very slowly and crystallized deep below the earth's crust. This slow cooling, combined
with the pressure from the overlying rock mass produced a well defined crystal structure
and a very compact stone. Its name is derived from its granular texture.


The term "Granite" has taken on a broader commercial classification, referring to
granite-type stones with similar characteristics, origins and having slightly different
mineral compositions. The majority are geologically related to each coming from the
same rock family. However, some are far removed in their composition and their
formation processes.

The trade term "Granite" has been incorporated in the names of some stones and this
can prove to be misleading. For instance, Granito Nero is a black limestone, the name
Belgian Granite is for a gray-black bituminous limestone, and Petit Granite is a black
limestone. The name of a stone can become an important point in relation to what one
thinks the stone is, just based on a name only and the intended use of the stone and it
expectations.

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