Gardening Landscaping Hardscaping

Stone Dust: What It Is, Uses, and Where to Buy It

Pile of stone dust

The Spruce / Adrienne Legault

After reading up on DIY hardscape projects, beginners often hit a roadblock when assembling supplies because they do not know where to buy "stone dust." There is much confusion over just what exactly this material is. At first glance, it probably will not remind you of stone, nor are you likely to associate it with dust.

What Is Stone Dust?

Stone dust is like a coarser version of sand. It's generally the byproduct of crushed stone.

In fact, said confusion is partly responsible for the difficulty you may have in purchasing it. Establishments in your area that sell stone, landscape supplies, etc. may not sell a product that goes specifically by the name of "stone dust" but may carry a suitable product that is similar but that goes by a different name. 

So before discussing where to buy stone dust, let's take a closer look at just what stone dust is because it is an important building material.

What Stone Dust Is

When stones are run through a crushing machine to make crushed stone, stone dust also forms. Its exact composition will depend on what kind of stone was run through the machine. For instance, sometimes granite is run through such a machine; in other cases, it could be limestone, for example. The machine has a screen that traps the larger material (that is, the crushed stone). The smaller material or "screenings" falls through the screen. Depending on the size of the holes in the screen used, it can be so fine in texture that it is basically a powder. This is what you are buying as "stone dust." But it may go by other names, such as:

  • Quarry dust
  • Quarry screenings
  • Grit
  • Decomposed granite

Decomposed granite is one of the more recognizable names in this group. Technically, though, it is a different material, occurring naturally. Note that you will also find the terminology "stabilized decomposed granite." This just means that a stabilizer has been added to the product to make it less susceptible to erosion.

Another material name that you are bound to encounter when doing research for building patios, etc. is polymeric sand. This building material contains additives that give it the ability to function as a binding agent. For example, you could use polymeric sand to fill in the cracks between stones when building a flagstone patio. In such cases, you would apply water to this filler afterward to moisten said additives, thereby activating their binding properties. 

How It Is Used

Stone dust is widely used as a setting bed for any of the various types of stone pavers (flagstone pavers such as bluestone being an example) used by homeowners in small projects. It can be smoothed to create a very flat surface and it is strong enough to support the weight of stone pavers, which can be quite significant.

Do note, however, that not everybody in the building trade would necessarily recommend stone dust as the first choice for such projects. Some observe, for example, that stone dust does not offer the best in the way of drainage qualities. Such objectors may prefer to use sand as a setting bed.

Where to Buy Stone Dust (Including How Much to Buy)

You can buy stone dust at most stone yards and quarries. Some excavation companies also sell it, along with the crushed stone, sand, gravel, bricks, flagstones, etc. that you might need for other projects. For a fee, most of these places will deliver the product to your property.

You may also be able to buy stone dust at your local Lowes or Home Depot. For example, you can buy it at Lowes in a 40-pound bag.

Read this article to learn how to calculate how much stone dust you need for your project.