Midnight Blue Granite Stabilized Pathway - Max McGraw Wildlife Foundation - Dundee, IL

What is decomposed granite?

Decomposed granite is a naturally occurring derivative of granite. Granite is the best-known igneous rock and can be found in its natural form all over the world. Some of its most popular natural features include Mount Rushmore and Yosemite Valley—beautiful facets to the earth’s scenery. However, granite has been mined and used for daily applications for thousands of years, from ancient hand tools to modern-day countertops.

Most often seen in architectural, roadway or countertop applications, granite is available in more than just slab form. Granite is a tremendously popular and abundant crushed stone. Kafka Granite is an industry leader when it comes to crushed stone, including decomposed granite: a naturally occurring material which has uses in a varied and broad spectrum of applications. DG, also referred to as rotten granite, is the product of granite weathered by wind, rain and temperature fluctuations over very long spans of time. Through extreme periods of weathering, granite formations become more fragile in structure and can be easily turned into decomposed stone.

Despite the possible association with the word decomposed, this granite is still strong granite, but it’s the product of large granite deposits that have been eroded. Naturally eroded granite is still harder and more durable than marble, but it is more stable and compacts better than gravel. Its applications range from patios, ballparks, driveways, pathways and landscapes to more high-traffic applications such as roads. While decomposed granite deposits can be found in various places throughout the United States, different colors are available in different regions.

Burma Red Hilltopper Warning Track - Yankee Stadium - New York, NY

“Decomposed Granite used with an engineered wax polymer to create a warning track at Yankee Stadium”

Kafka Granite offers both standard and stabilized decomposed granite. Although we have a variety of locally sourced decomposed granite, often times, we will crush various colors of granite, quartz, marble and recycled materials (mirrors, porcelain, electronics glass) to mimic the qualities and size of decomposed granite. Our produced DG provides more color variety for your project’s needs, while retaining the same qualities that made decomposed granite a popular solution for pathways, trails, bike paths, patios, and more. Stabilized decomposed granite is the go-to option for projects that require enhanced durability coupled with stability and permeability, such as high-traffic pathways or ballyards.

How is decomposed granite mined?

Decomposed granite is usually gathered from a quarry or, in Kafka Granite’s case, many quarries around North America. Wisconsin, where Kafka is headquartered, is teeming with quarries as a reminder of glacial movement after the Ice Age. Quarries may have different methods of acquiring the rock from the land, but decomposed granite is most commonly dug up from the earth like soil. Once excavated, the next step for the granite is getting sent through the screening process.

Kafka Granite hones state-of-the-art crushing and screening technology, which adds impeccable customization to your project or needs. Decomposed granite formations are naturally fragile due to their weathering (which is what makes it a decomposed granite). The fragile nature of true DG renders it somewhat easier to acquire than solid slabs of stone, and therefore, more economically and environmentally friendly to mine.

Where does decomposed granite come from in North America?

Granite quarries exist across North America. There isn’t one concentration of granite, like gold for example, since it exists in much of the earth’s crust. In fact, depending on the quarry or area the granite comes from, granite is available in a myriad of colors. Different parts of North America produce different veins of granite, which makes it wise for granite crushers and distributors to source both locally and nationwide in order to take advantage of the incredible natural colors.

Why is granite different colors if it’s all coming from the earth’s crust?

The composition of granite is what’s responsible for the variety of colors found globally. Granite is made up of:

  • Feldspar
    Rock-forming mineral, most abundant mineral in earth’s crust
  • Quartz
    Second most abundant mineral in earth’s crust
  • Micas
    Silicate minerals

The color variations of granite are due to several in-depth chemical reasons. However, most simply put, granite takes on different colors depending on the colors of the most abundant feldspars in an area. The color of feldspar depends on its own mineral composition.

How much does decomposed granite cost?

The cost of decomposed granite varies depending its size, color and whether it’s standard or mixed with a binder. The most inexpensive granite will be the most common in color and standard—without a stabilizing binder. However, other factors play into price, which can make costs hard to estimate unless you know details of your project and the decomposed granite product you want. These factors include:

  • Is it natural decomposed granite or is it produced?
  • How local is the DG you want?
  • How abundant is the DG you want?
  • What is the demand for that particular DG?

However, decomposed granite prices can fluctuate greatly depending on the market price of this commodity. Note, though, that DG is often seen as a very cost-effective alternative to cement or concrete pathways and driveways. The benefits of decomposed granite also often outweigh the benefits of its counterparts, such as its impressive permeability. Being permeable is one of DG’s greatest assets. By allowing great amounts of stormwater (excess rainfall that collects on or travels over pavement) to permeate its surface, stormwater runoff is being eliminated or greatly reduced. Stormwater runoff can carry pollutants and debris into our water. It’s important to consider reducing the harms of polluted rainwater running into our lakes and rivers, which can be achieved through permeable surfaces instead of hard pavements.

How does Kafka Granite use decomposed granite?

Kafka Granite realizes the potential for decomposed granite aggregate in a variety of applications. Some of these applications include:

  • Pathways and trail systems
  • Driveways
  • Landscaping
  • Ball yard infields
  • Ball yard warning tracks

While we crush and screen more aggregates such as granite, quartz, marble and recycled materials, we fully realize the many uses for a stone as durable and versatile as decomposed granite.

Granite can resist deterioration, performs well against adverse weather and temperatures, and is a very dense stone. When compacted, decomposed granite is a permeable ground cover, ideal for things like pathways or ball fields where you may want water to be able to slip through and not form puddles on a surface.

Standard Red Cedar Granite Pathway Mix - City High School Shot Put - Iowa City, IA

“Standard Decomposed Granite used for a shut put court.”

Kafka Granite offers an impressive variety of colors to go with whatever aesthetic you need for your specific project and application. Our naturally occurring decomposed granite is available in reddish-brown or goldish-brown—a color of decomposed granite that can’t be found in many DG quarries in other parts of the country.

How can decomposed granite contribute to sustainable efforts?

There are several ways in which decomposed granite can contribute to your LEED certification efforts. By earning points to be Leadership in Energy & Environmental Design certified, your project can reach varying levels of sustainability. Striving to build a green eco-friendly project will lend to the environment for years to come.

LEED certification points can be acquired through using decomposed granite in the following ways:

  • Compacted decomposed granite is a very permeable material. Permeable surfaces lend themselves to aiding the soil and returning water to the water table. Permeable surfaces are also beneficial in that they won’t collect water and develop standing pools, which could lead to pests or other detrimental side effects
  • Depending on where the granite comes from for your specific project, using a locally produced decomposed granite could earn you regional priority LEED certification points
  • Since decomposed granite is a natural product, as well as organic stabilizers which can be used in conjunction with decomposed granite, LEED points can be earned for using this naturally occurring and abundant decorative material
Midnight Blue Granite Stabilized Pathway - Max McGraw Wildlife Foundation - Dundee, IL

“Decomposed granite combined with an organic binder create beautiful, yet practical, nature paths and bike trails.”

Decomposed granite is beautiful, varied in color, strong and can be used in a myriad of applications and projects. Whether you need subtle hues for a pathway through a nature reserve or specific mixes for your commercial landscaping project, Kafka Granite knows the incredible variances that exist with decomposed granite. Our state-of-the-art facility can provide the natural or produced decomposed granite you’ve been looking for—let’s talk about your project today.


Hilltopper* is a registered trademark of Stabilizer Solutions. Kafka Granite no longer utilizes Hilltopper* in the composition of their ballfield mixes.