How Granite is formed: Why cracks and fissures are frequent
When choosing a granite slab or perhaps admiring your newly installed countertops, you may notice intermittent lines in the stone. Do not panic! Some people assume that these are cracks and that the integrity of their countertops will be compromised, but in most cases there is nothing to worry about. The difference between a crack and a natural granite fissure is an important aspect of enjoying the natural beauty of granite.
A fissure in a slab of granite is a natural cleft in the rock caused by God or “Nature”. When the stones form underground, a gap may develop in the material for any number of reasons, and this gap presents as a fissure when the slabs are mined from the ground.
Rock mining companies pull stone out of the ground in large rectangular cubes, then slice those rectangular cubes like bread. The slices become the individual slabs, and if those slabs have gaps or fissures, the mining company will fill them in with quartz crystals and a penetrating resin. The resin used to seal these fissures lends to the overall strength of the slab itself.
A crack in granite occurs when there is an accident after the slab is resonated and polished. The crack will go all the way through the stone and be detectable by touch. This is the result of unintended breakage, and is not already filled in with quartz, resin, or epoxy.
