Granite vs Sandstone

The first of the two materials we are going to look at in this match-up is a tried and true natural stone. The second is also an effective material, but perhaps not as frequently considered. In this consideration of granite vs sandstone we are going to delve into some information regarding each of these materials. We will look some key aspects of natural stone materials and compare the two stones we are considering. Along the way, we will mention some reasons the characteristics we are talking about are beneficial.

Briefly Considering Granite

Before we begin describing natural granite it is good to take a moment to explain that our use of the word granite here is not in the scientific sense. Geologists classify granite using very specific traits and mineral content. We though, are speaking of natural stone as granite in the sense use by the commercial stone industry. Thus, some materials that are technically a different rock, geologically speaking, but have traits consistent with granite, are encompassed in our use of the term.

Granite is an igneous rock that forms from volcanic activity. Note how Wikipedia expresses this concept:

It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground.

This natural stone is composed of a variety of minerals and mostly of quartz, feldspar, and plagioclase.

Sandstone Summarized

Sandstone is a natural, sedimentary rock that is made up of grains of material that are sand-sized. These particles are bound together by a "cementing" material. Sandstone is one of the most common types of sedimentary natural stone. It can have a high quartz content and is used in various ways. Although sandstone can be formed from actual sand, technically the term "sand" in the name refers to the size of the particulates of which the stone is composed. These particles can be of different materials.

Comparing Aspects of Granite & Sandstone

For our comparison of granite vs sandstone, we will look at some specific aspects of natural stone and then comment a bit on each of these materials. Organizing the material in this way will give us the opportunity to see the similarities and differences between granite and sandstone, but also mention some practical results of the trait under consideration.

Granite vs Sandstone Hardness

The first characteristic that we will look at in our comparison is the hardness. This is measured by performing a scratch test on the stone being measured. The test is done on various parts of the slab being tested. The tool used to perform the test has a known hardness and by firmly scratching the stone with various tools (or another materials), its hardness is determined. The Mohs scale of hardness is how the hardness is measured. The harder the material, the higher the number.

Hardness of Granite

Natural granite is a hard stone. It resides on the Mohs scale at around 6 to 7. Granite's hardness is expressed in a range because of the mineral variety that can make up the stone. Therefore, some granite may be closer to 6 in hardness and other slabs may be near the 7 mark.

Sandstone's Hardness

The other contender in this versus comparison of natural stone, sandstone, might have you thinking that it is not as hard as its counterpart. However, you would be mistaken if you bought into that thinking. Sandstone, like granite also lives in the hardness range of 6 to 7 on the Mohs scale. Again, the minerals that make up the stone contribute to the hardness of that stone.

Why Hardness is Important

So why does the hardness of a stone make a difference? Simply put, it is related to the durability. Earlier we mentioned that measuring the hardness of a stone involves scratching the stone. In the practical sense then, the harder the stone is, the more resistant to scratching it will prove to be. When you have a hard surface in a business or home, this is an important quality to have. For example, flooring, walls, and counter top surfaces have a lot of interaction with other materials. The harder the stone these surfaces are made of, the longer they look good.

Comparing Porosity of Granite & Sandstone

The second facet of stone we will look at briefly in our granite vs sandstone comparison is porosity. Porosity is the term used to describe how easily a natural stone or other material absorbs liquids such as water and oil. The more porous, the faster the material "drinks" the liquid. Virtually all natural stone is porous and absorbs liquid to some degree. The question though is how porous are granite and sandstone?

Granite's Porosity

Granite slabs are available in different grades. One of the traits the grade communicates to the buyer is its porosity. Stone is not all identical and one of the ways the properties of a slab are expressed to consumers is the grade. The porosity of granite varies just like the hardness does. In fact, a slab's porosity might vary. in other words, you might perform an absorption test on one part of a slab and find that it consumes the water a bit faster than another part. This is normal and is not a problem. Periodic natural stone sealer treatments make the stone more resistant to absorption.

Pores of Sandstone

If you are thinking that sandstone is like granite regarding porosity, then you are correct, to a degree. Like granite, sandstone varies in its porosity. Additionally, like granite, sandstone is available in various grades. Though sandstone is a sedimentary rock, it also is the stone that is changed through pressure and heat to become an entirely different stone called quartzite. This transformation does not happen quickly. Rather it happens over a long period of time. Quartzite is less porous than sandstone. But think about this: as the sandstone transforms it progresses through different levels of porosity. So, sandstone that is further into its transformation to quartzite will be less porous than basic sandstone. What's the point? Well, simply put, sandstone too has varying porosity.

Why Porosity Matters

At this point you may be thinking, "So what if the stone gets wet, it will dry out right?" That is true, but think about this, many liquids are water based but are not just water. Other liquids are oil based and like the water based ones they can have other substances in them. Water and oil based liquids that are absorbed by stone have the potential to stain the material. When the liquid goes into the stone it is water based. But when the water evaporates, the other (non-water) substances are left int the stone. These substances discolor the stone if they are not transparent. In other words, the water (or oil) becomes a delivery system for stains. As we previously mentioned though, a simple maintenance program of sealing the stone helps protect it from these stains.

Design Compatibility (Color Selection)

The last aspect of our granite vs sandstone comparison we will consider is the color availability of each material. This facet of selecting natural stone is a key part of the design of the project. The color though is not the only visual trait that contributes to good design. The pattern, texture, and number of colors also plays a role in the compatibility of a slab with a given design style. SO how do our contenders measure up in this area?

Designing With Granite

One of the great things about natural granite is the variety in its appearance. For designers, decorators, and architects, this translates into flexibility in the project's design. Granite slabs range in a wide variety of colors, patterns and textures. One stone may have several colors in it with different consistencies in grain. The next stone may have such a fine, consistent grain, that it looks almost like a solid color from across the room. These variations lend themselves to flexibility. True, there are several granite colors that seem to be more popular than others, but the selection is very, very broad.

Sandstone and Design

In a similar way, sandstone slabs also offer variety, although not to the degree of diversity that granite does. Still yet, sandstone does form in a number of colors, and it is a material that may be used in conjunction with other stone materials. Additionally, natural stone can also be mechanically textured using tools such as one of these CNC stone antiquing, texturing, and honing kits.

In the end, the real verdict when deciding on going with granite vs sandstone is really up to the consumer. Being familiar though, with the similarities between many natural stone materials allows the consumer to know what to expect. Conversely, being familiar with the differences between two specific materials helps buyers discern which material might be better for a given application.