A tale as old as time …
What is Granite?
Granite is the earliest, oldest, and one of the hardest forms of stone. Classed, officially, as an intrusive igneous rock, it is – as its classification suggests – formed underground from volcanic material: hot liquid magma rises up underneath the earth’s surface and, lacking the escape hatch of a volcano, will cool – over time, trapped beneath the earth’s crust – to form the hard, crystalline rock that we know as Granite.
While all granites share a similar method of formation and common defining mineral components (Quartz and Feldspar, with a touch of Mica commonly contributing an element of ‘twinkle’), the properties and looks of individual granites will vary according to the specifics of their geography and history.
How does the formation of Granite affect its Appearance?
The crystalline formation of granite gives it a typically granular appearance and a tendency to lack the poetic sweeping gestures of marble. However, texture will vary with the fineness of the grain of the stone, and markings and tonality range from the more clichéd pizzicato ‘speckle-with-sparkle’ variety – sometimes associated with late 20th Century aspirational kitchen surfaces – to the more magnificent marblings that typify Mother Nature’s lesser known, if infinitely more romantic, granitic oeuvre.
Our newly installed Green Granite surface on our ground floor kitchen display is a honed (matt finish) Italian mother-piece creation of Mama Nature. It has had many admirers to date – one of whom sat at its round-edged surface (technically known as a ‘double bullnose’) with his favourite toy dinosaur of the day keeping him company, and declared it to be made of pure Emeralds. We chatted some about the volcanic activity that created it while his own mama worried about the possible damaging effects of dinosaur claws on granite, we reassured the stone was more than up to the challenge of resisting any onslaught from this late-stage prehistoric companion.
The Hard man of Kitchen surfaces
The baseline mineral composition of granite means that it measures an effective 6/7 on the MOHS scale – a scale used to measure the ‘hardness’ of minerals relative to each other in terms of ‘scratch-ability’. The scale runs from 1 to 10, softest to hardest – those lower on the scale can be scratched by those that rank higher. Granite is considered harder than glass and harder than a knife blade – you will blunt a sharp knife if you cut directly onto a granite surface, and you will struggle to scratch this material with the average wear and tear of domestic life.
The relative hardness of individual granites will depend on the mineral mix of each – the higher the proportion of relatively softer minerals, the more care you may need to take in maintaining the surface.
Porosity and Stainability
A relatively open internal structure may give Granite a tendency to be porous and thus susceptible to staining – degrees of porosity will vary according to the fineness of the grain. There are different views on how, or if, to manage this vulnerability – some recommend that granite should be sealed with a penetrating sealant as it is installed, others (mostly Stateside) suggest that you can ‘maintain’ it with mineral oil – as a purely cosmetic means of intensifying depth of tone and camouflaging stains – and others still that if you leave the stain to find its way over time into the pore system of the stone that it will become ‘invisible’ by forming just another part of the earned patina that adds to individual character.
We normally recommend applying a suitable sealant to avoid unnecessary staining but are also attuned to the beauty inherent in earned patina: it is our belief that all natural surfaces, especially those as ancient as granite, be allowed to embrace the marks of a live well lived and to carry the memories of a damned good party.
We caution against mineral oil which, while having its place in maintaining a butchers block or enhancing a non-porous soapstone, may leave either a greasy residue or blotchy patches on the stone, and risk attracting dust and dirt.
Heat Resistance and Density
Owing to its high heat origins, granite provides a good heat resistant surface known to be reasonably forgiving of hot pans placed directly on its surface. Having said this, it is still vulnerable to thermal shocks (the shock of a sudden change in temperature) which can cause fractures in the stone or other forms damage. For this reason, we always recommend the use of trivets or heat mats when placing hot pans on stone surfaces and caution that anyone who places hot pans directly onto any stone surface, including granite, does so at their own risk.
Darker coloured granites, as a general rule, tend to be denser and harder than those that incorporate lighter tones: increased density will, generally speaking, lower porosity and increase heat resistance.
Finishes for Granite
Your choice of finish will affect how the granite looks and feels – a polished surface will add a sheen of elegance and formality to a space, while a honed surface may give a more casual feel and be a more tactile temptation (we regularly stroke ours like a pet). A honed surface may also add a frisson of excitement to the normally mundane task of a wipe down with a damp cloth as you reveal the deeper tonalities that lie beneath a matt finish surface.
Edge Profiles are also important. The granite surface on display in our Wimbledon Village showroom has a double bull nose edge – a softly rounded, double stacked edge with a curved end for sociable seating. If you want to know exactly what that looks like, you may have to visit our showroom.
In the meantime …
