When a listing describes a “flagstone” patio, what do they really mean? Flagstone is a broad term used to describe a range of sedimentary and metamorphic rocks. These rocks are called flagstones because they can be easily split into flat segments that are used to pave patio walkways and build rock walls, in addition to other home applications. Essentially, when a stone is called a flagstone, it doesn’t point to one specific stone, but instead any stone that is suitable as a paving stone.
The bluestone is separated from the rock in the quarry into large rectangular blocks by parallel cuts with saws using diamond-tipped blades .
Types of Flagstone
A type of blue-gray sandstone but much more dense
Very flat with a rough texture. Classical looking.
Primarily found in Northeast (Pennsylvania and New York)
Shades of blue, gray, and purple
Dense, tough paving, non-slip surface, holds up to Northeastern harsh winters
Requires proper sealing to preserve color, to resist chlorine or salt water and to protect from scratching and staining.
Sandstone (common type: Arizona Flagstone)
A sedimentary rock formed by layers of sand
Contemporary or earthy look
Most commonly found in the Southwest
Soft pastel colors from beige to red: Pinks, buckskin gold, and dark red
Cooler surface temperatures in summer. Weather resistant in dense, tightly packed varieties.
Porous and tends to absorb water which can cause damage in freeze/thaw cycles. Should be sealed to avoid staining.
A form of metamorphosed rock
Glossy, smooth surface. Ageless appearance.
Commonly found in Idaho, Oklahoma and Northern Utah
Wide range of colors including silver, gold, and lighter tan, blues, grays, and greens
Resistant to wear and tear, rain, and harsh chemicals. Non-slip surface, more stain resistant than sandstone.
Prone to etching, hard to shape, requires routine maintenance to prevent soiling on its rough, textured surface.
A common sedimentary rock composed of calcite
Natural split surface, can be polished. Elegant.
Commonly found in Indiana
Range of colors including gray, beige, yellow and black
Good for humid climates, weather-resistant, long-lasting
Very heavy, susceptible to damage from acid
A compacted variety of limestone
Weathered look with pitted holes
Found naturally in Oklahoma and Texas. Quarried in Western US states.
Various shades of brown, tan, and gray-blues
Durable, higher-end stone, stays cool for outdoor surfaces
Can be difficult to finish and maintain because of surface pits
A metamorphic rock layered with clay-like minerals
Very flaky, softer than sandstone or quartzite. Antique-looking.
Commonly found in Pennsylvania, Virginia, Vermont and New York
Silver gray, green, copper
Easy to chisel and shape, usually used for wall-cladding
Easily splits, limited availability in large sizes, requires sealing for stain resistance and to reduce efflorescence
Important things to remember when you select flagstone:
Choose flagstone that’s available in as many shapes, sizes and thicknesses as possible.
Beware that glittery flagstone can lose this sparkle under wear and tear.
Brightly colored stone may prove softer than more uniform muted tones.
Has this stone been tested in residential landscapes over time?
Does the stone originate near my project site for minimal shipping charges.
Is the stone widely available through different sources so I can compare costs?
Where water is mineral rich, beware of dark colored stones that show efflorescence.
Flagstone vs Bluestone: Which One Is Right for You?
Considering that bluestone itself is a form of flagstone, you truly can’t go wrong with either material. The stone that is best for you depends on your unique project, design, and needs. Typically, bluestone is considered the sturdier of the two and will hold in place better for a more resilient finish to withstand the elements. With blue and gray tones, this stone is a more classic, formal design choice for a clean, even aesthetic.
Flagstone, on the other hand, offers a more earthy look for contemporary landscape designs. Since it comes in a variety of shapes, textures, and colors, it’s a more flexible choice when designing your space. Plus, it provides traction with natural ridges to limit slipping and helps reduce surface water pooling.