The facts
What granite actually is
Granite is classified as coarse-grained felsic intrusive igneous rock of quartz, alkali feldspar and plagioclase; in the stone trade the word also covers gabbro, anorthosite, gneiss and charnockite, with the composition Quartz SiO2, K-feldspar KAlSi3O8, plagioclase, biotite and hornblende. It crystallises in the aggregate system.
Colour comes from pink and red from K-feldspar with trace Fe3+; grey from plagioclase; dark minerals set the overall tone, which is also what a laboratory looks at when it is asked whether a colour is natural.
Specific gravity around 2.60-2.80. Cleavage: feldspar cleavage visible on fresh surfaces. Those three numbers separate it from most of what imitates it.
Where granite comes from
Granite is produced at Barre, Vermont, USA (Barre Grey), Rustenburg and the Bushveld Complex, South Africa (Impala Black, actually gabbro), Espirito Santo and Ceara, Brazil, Ilam and Rajasthan, India and Finland (Baltic Brown, a rapakivi granite).
The locality is part of the description, not a footnote — two stones of the same weight from two of these places are not the same stone.
How granite is treated
Resin-impregnated and mesh-backed slabs are standard in the fabrication trade; sealing is routine on kitchen tops. Some granites emit measurable radon and gamma radiation from accessory zircon, monazite and uraninite - levels are almost always trivial, but a few high-K feldspar and syenitic stones are elevated and this occasionally matters for large interior installations. 'Granite' in the stone trade is a commercial category, not a petrological one. Not CITES.
Treatment changes value, sometimes by a multiple, so it belongs in the description before the price and not after the sale.
What granite is confused with
In the trade granite is most often mistaken for, or substituted by, Gabbro, dolerite, anorthosite and gneiss sold as granite, Engineered quartz surfaces or Porcelain slabs printed with granite patterns.
Because the material is opaque, refractive index is no help. Specific gravity around 2.60-2.80, hardness of 6-7 (quartz-controlled), streak and magnification do the work instead.
What granite is used for
Demand for granite comes from architecture and interiors, heavy industry, decorative objects and memorials, which is why one price per carat never covers it.
We quote each application in the unit that trade actually buys in, by the square metre, by the tonne or by the piece.
Durability and care
Granite is 6-7 (quartz-controlled) on the Mohs scale, with feldspar cleavage visible on fresh surfaces cleavage.
With no cleavage plane to worry about, the practical limit is abrasion rather than breakage, and it takes daily wear well.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What granite costs
As a guide, granite trades around $30-150 per square foot installed; exotic Brazilian and Indian stones $100-400 per square foot.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is granite treated, and how?
Resin-impregnated and mesh-backed slabs are standard in the fabrication trade; sealing is routine on kitchen tops. Some granites emit measurable radon and gamma radiation from accessory zircon, monazite and uraninite - levels are almost always trivial, but a few high-K feldspar and syenitic stones are elevated and this occasionally matters for large interior installations. 'Granite' in the stone trade is a commercial category, not a petrological one. Not CITES.
Where does granite come from?
Barre, Vermont, USA (Barre Grey), Rustenburg and the Bushveld Complex, South Africa (Impala Black, actually gabbro), Espirito Santo and Ceara, Brazil, Ilam and Rajasthan, India and Finland (Baltic Brown, a rapakivi granite). Origin affects price, so we name the locality rather than the country on every quote.
Is granite hard enough to wear every day?
Yes. At 6-7 (quartz-controlled) on the Mohs scale with no cleavage plane, it handles daily wear well. The practical limit is gradual abrasion rather than chipping.
How much does granite cost?
Indicatively $30-150 per square foot installed; exotic Brazilian and Indian stones $100-400 per square foot. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is granite confused with?
Most often Gabbro, dolerite, anorthosite and gneiss sold as granite, Engineered quartz surfaces and Porcelain slabs printed with granite patterns. Since the material is opaque, separation relies on specific gravity near 2.60-2.80, hardness and magnification.
What is granite used for besides jewellery?
architecture and interiors, heavy industry, decorative objects and memorials. Each of those trades buys it in a different form and a different unit.
Related stones
Looking for granite?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about granite