What is the difference between granite and quartz? Which is better, granite or quartz? These are probably the most frequent questions that people ask us. The answer to the first is (fairly) simple… and to the second, more complicated. At the simplest level the difference is between natural and man-made stone.
Granite is natural; quartz is man-made. What is called “granite” in our industry is not necessarily what a geologist would call granite. In practice, “granite worktops” are made from a wide variety of stones, all of them hard, and all of them natural – granite worktops are made from rock that has come out of the ground.
Quartz on the other hand is man-made. It is properly called “engineered stone”. To make it, small pieces of natural stone, glass, mirror and other hard products are mixed with a petro-chemical resin and compressed. For some products dyes are injected so as to give the appearance of natural veining, but the product itself, however much like a natural stone it looks, is manmade.
The second question, “Which is better?” is more complicated. Our general rule of thumb is to recommend granite in dark colours and quartz in light colours. Here are the reasons:
Dark “granites” tend to be genuinely igneous rocks – crystallised out of molten magma way beneath the earth’s surface. As a result they are low in porosity and have great resistance to any penetration by stains. In addition, being dark or black, even if a stain WERE to penetrate, there is very little chance that it would show.
Lighter “granites” are generally metamorphic rocks formed from the coming together of sands and gravels, with other minerals percolating through in solution, and the whole layer being heated and compressed over time. They tend to have more and larger pores than the igneous rocks, AND the light colours mean that any stains that penetrate can be visible. Getting a sub-surface stain out is all but impossible, although they generally fade over time, and are far less obvious where there is some colour in the stone. We always urge customers who buy light coloured granites – which many still do, due to the beauty of the natural patterning – to watch out for any break-down in the surface sealing, especially near the sink. Where the stone becomes darker when wet, you know that water is entering the surface, and where that kind of water-bridge is present in the stone, a colour in solution can very easily get beneath the surface.
Because of its resin base, quartz is completely non-porous. That doesn’t mean it is completely proof against all staining, but that no stains can get below the surface. A pen mark or curry stain may need some treating, but it will only be on the top of the stone.
A patch of water on an unsealed piece of Colonial White granite.
The darker patch left after the water has been wiped off, showing water penetration into the stone. When this starts to happen near your sink you need to reseal the granite.
Although both granite and quartz are very hard, it is nevertheless possible to scratch them – with other pieces of stone, ceramic or glass, or diamonds etc. One difference we have observed in samples of granite and quartz in our office is that dark granites tend to scratch to a dark colour, whereas quartz looks lighter where it is damaged. The result of this is that black quartz can look far tatty more quickly than similar-toned granites. This is a significant advantage of black granite. It would probably be fair to say that the high-end brands of quartz seem to suffer less from this issue, and, as ever, patterned stones disguise issues better than plain ones. It would also be fair to say that the big samples in our office suffer a very high level of wear and tear, being bashed against and slid over each other – worktops in a normal kitchen will not experience anything like the abrasion we see here.
Fine scratches on a piece of Nero Assoluto in our showroom, where other stone samples have been dragged across it. The coin is a 5p piece.
Scratches on the edge of a piece of black sparkly quartz, where other samples have hit or scraped over it. Note the lighter colour in the scratch. Both these images show EXTREME abrasion – they are not kitchen-typical.
For those reasons, it is probably clear why we tend to favour quartz in light colours and granite in dark. There are a few other differences, though, where one or the other product can have the edge.
Because of the plastic element in the composition of engineered stones, quartz has a greater tensile strength than most granite as used for worktops. “Granites” themselves vary greatly in this respect, being very different kinds of stone; the truly volcanic stones are very strong, but some of the larger grained metamorphic rocks are comparatively weak. This can mean increased standard minimum clearances for cutouts, reduced maximum overhangs and, sometimes, overall run lengths.
With its higher strength, however, quartz worktops can be manufactured with easier tolerances, and at only 20mm thickness if required. For some styles of kitchen a thinner worktop is preferred, and in that case quartz is definitely the way to go.
The resin/plastic content in quartz can be attacked and broken down by ultraviolet light. Therefore, for garden tables, barbecues and any other outside application, only natural stone can be recommended. If a manmade look is wanted, then Dekton® could be a good option… have a look at our Dekton sister site here.
Remember, both granite and quartz are top end worktop materials. In some ways it is a bit like comparing a Porsche and a Ferrari – to anyone driving an old Ford the differences may seem academic! And it is important to remember that; both products have great advantages in many situations, and there is no point overplaying the differences when, compared, say, to wood and al its maintenance issues, both stones are so superior. We hope that this “granite and quartz” article will be useful though – please call us on 01293 863992 or use Live Chat if you need more help.
For an article looking at stone worktops versus laminate worktops, see here.