Our decorative groundcover is all natural stone quarried from unique deposits of granite, shale, shist, marble, sandstone, ryolite, and volcanic rock throughout Arizona and the Southwest. Click on MDI Mining for more information on how decorative rock is made. MDI Rock carries an extensive selection of groundcover in colors and shades varying from white to almost black and most colors in between. Common sizes range from 1/4" up to 1" with many different screening qualities in between.

Below are some FAQ's about Granite/Groundcover:

All groundcover contains particles of the stone smaller than the size indicated all the way down to dust, these particles are referred to as "fines." There are different gradations of these products which determine the percentage of fines. The following terms describe the amount of fines in a particular product.

Minus: A lot of fines, sometimes up to 80% of the product will be smaller than the size indicated.

Example: 1/2" minus Cinnamon Brown
                1/2" stone =30-40%
                Smaller pieces down to dust = 60-70%

Screened: Some of the fines have been screened/sifted out. Typically screened rock will have 20-40% fines.