What Is Bluestone?

Bluestone for patios is durable, attractive, and ideal for all kinds of uses. Bluestone is a natural stone that can also be used for pool decks, stone steps, or entryways. Both types of U.S. bluestone have long been used as pavers in hardscapes and are also commonly used in landscaping projects. Blustone can be expensive as it's rarer than other forms of natural stone being only available from certain parts of North America.

Read on to learn about the highly durable and adaptable natural material of bluestone.

What is Bluestone?

Bluestone is a common type of sedimentary rock, meaning the stone is formed from deposits accumulated on the Earth's surface. Bluestone is used for construction. There are two varieties: Pennsylvania and Shenandoah bluestone. Pennsylvania bluestone, which is a sandstone, is a type of sedimentary rock made of sand-sized grains. Shenandoah bluestone, which is a limestone, is also a type of sedimentary rock, but it's made mostly of calcium carbonate.

Bluestone Pavers Color and Shape

Bluestone pavers or slabs come in several sizes and shapes: they may be cut in uniform sizes such as squares, rectangles, or they might be cut for a more natural look with jagged edges and irregular shapes. What you use in your paving project is a matter of taste, although the irregular sizes lend themselves to more free-form designs such as walkways and stepping stones. Uniform pieces will be easier to work with, of course, since mapping out the area to cover will require less work.

The Pros of Bluestone in a Landscape

Bluestone is durable and will last many years. Its natural earth-tone colors are gracious and attractive and complement almost any landscape. Its rough surface also means that it rarely gets slick or slippery. Further, it's readily available and it comes from quarries in the United States, so there is no overseas shipping to add to its cost, which is already somewhat high.

Bluestone can tolerate all kinds of weather and temperature fluctuations—you can incorporate it into your landscape wherever you live, whether you endure snow and ice or desert heat.

The Cons of Bluestone in a Landscape

An obvious disadvantage to bluestone is its cost—any natural material will be more expensive than a manmade material such as concrete pavers or bricks, and bluestone is especially prized for its beauty. It can be harder to install bluestone than concrete or bricks because it is commonly irregularly shaped and also may not have a standard depth.

The darker colors can get hot, so bluestone might not always be a good choice pool-side where you and your family are walking barefoot. 

Another consideration is that you will need to seal it to protect it from damage due to debris, salt, or chemicals, such as chlorine.

Bluestone Styles

The two types of bluestone come in various styles including the following:

• Gauged: The gauged look is created by laser-guided saws and precision milling equipment. This is a thermal pattern bluestone with consistent dimensions.
• Natural Cleft: A split stone vs. sawn, it possesses a textured surface that undulates throughout. This can increase the character of the stone and make it more interesting to some buyers.
• Thermal: This bluestone has been rapidly heated with a high-temperature torch after sawing. The result is a surface that "pops" leaving a dimpled texture similar to a golf ball.
• Polished: A common finishing technique of countertops, the smooth surface is created with diamond sanding discs that make the stone as smooth as glass.
• Full Color: This stone was collected from different deposits causing the colors to vary from light blue to dark brown or rust. They can have a color shift within a single stone.
• True Blue: A label for bluestone that encompasses a range of different shades of blue but where the color stays consistent throughout a single stone. This style would exclude any darker spots or blemishes such as fossils or iron deposits.
• Sawn: A sawn finish has been left "as is" after being cut for the first time. It will be rougher and more jagged and typically has a light shade of bluish-gray.
• Snapped Edge: A broken stone with a rough and irregular texture exposed, this is also referred to as Rock Facing. Used often for retaining walls, the "snapping" that creates this look comes from a hydraulic press or it can be achieved by chisel and hammer.

Tips for Buying and Installing Bluestone

Before choosing your bluestone pavers, first, decide whether you want irregular pavers or uniform size pavers. Irregular will be harder to install but may fit better with your existing garden design. 

Be aware that bluestone is a natural material, so even uniform sizes will have imperfections: small clefts or crevices, or rust stains, for instance. Consider these irregularities part of the beauty of the stone. Here are more tips on installing bluestone:

• Bluestone generally is 1 inch to 1.5 inches thick. Typically, a palette of 1.5-inch bluestone pavers will cover about 180 square feet, while 1-inch-thick bluestone pavers will cover approximately 220 square feet.
• You can install bluestone on a range of materials including sand, cement, or gravel, just like most other pavers. It's important to compact the soil and properly prepare and level the area where you want to lay the bluestone.
• Edging bluestone pavers stabilizes it and will keep it from shifting.