Fabricators frequently group granite countertops into grades labeled 1 to 3 or 1 to 4. Frequently, they will only differentiate these stones by price rather than giving an explanation as to why one stone will be in one grade versus another. Grade 3, or group 3, granite is often significantly lower in price than the grades above it. Understanding why can help you make an informed decision about whether this savings is worth it.
Commercial or Utility Grade
Frequently, a fabricator, stone yard or quarry will designate a block of stone as group 3 meaning that it is suitable only for commercial use. This means that the stone may not be pleasing to look at. It may have uneven color, large color spots such as black in an otherwise light color slab or it may be uneven in granular pattern. These are not defects, but many fabricators will price the stone to sell to a commercial building where looks are not as important as they may be to a homeowner designing her kitchen.
Some stones are downgraded to grade 3 because there is only a small section of the stone that is workable. Some of the stone may have been structurally unsound and cut away, the stone may have had large areas of uneven color, which were removed or there may have been large pits, crystal voids or other areas that factory cut away. What is left is a small sized slab. While a grade 1 or grade 2 granite may come in a 10-foot long section, a grade3 slab may be shorter. This means that there may be more seams in a counter or there may only be enough to use on a bathroom vanity rather than in a kitchen.
Fissure and Voids
Not all granites are created equally. Many stones labelled granite in the industry are igneous rocks of similar density to the rock granite but may have different mineral makeups. Sometimes this results in a stone that has more fissures or cracks running through its surface. These cracks can be repaired with an epoxy resin to help give the stone better integrity.
With group 3 granites, there are frequently many fissures or fractures in the stone, which means either a lot of resin went into repairing it or the stone was left weaker with the fissures intact. When the resin used to repair it becomes visible, the stone may be downgraded, even though it is still structurally sound.
Some fabricators group their granites solely on cost. While a group 1 granite may cost up to $400 per square foot, at time of publication, a group 3 granite is usually much less expensive. Sometimes this is because the stone is readily available and easy to get for a lower price and other times it's because the stone is not as good a quality as others.
Group 3 granite can cost as little as $10 to $20 a square foot. Find out if the reason is because someone views it as unattractive or if the stone is small or structurally flawed. You may find you enjoy its color and get a great deal or it may be worth staying away from.