There is perhaps no landscape product terminology more confusing than “gravel” and “stone.” This misunderstanding sometimes leads to customers ordering the wrong material. It’s not a simple answer, but hopefully in this blog post we can clarify what exactly is the difference between gravel and stone.
Where gravel and stone come from.
The generally accepted definition that distinguishes gravel from stone is their source:
- Gravel is a naturally occurring earth product that is composed of rock that has broken down due to erosion and time
- Stone is a man-made earth product that is mechanically processed usually by crushing and sifting.
This, however, is not particularly helpful to the average consumer who is looking to do a project in their yard. In that sense, it’s better to think of gravel as a generally round, smooth rock, and stone as a sharper-edged aggregate product. The next step is to identify the size of stone they need for their project.
“I know what I want, I just don’t know what to call it.”
In the horticultural world, there are common names and botanical names. For example, what someone might call an “arborvitae” another might call “white cedar” – which isn’t a cedar at all. The botanical name for arborvitae is “thuja occidentalis.” When ordering plants, landscape designers will refer to the botanical name. But what about earth products?
Fortunately, the American Society for Testing and Materials (ASTM) has defined certain sizes into numbered categories to eliminate some confusion – as shown in the chart below.
ASTM C-33 Standard Specification for Concrete Aggregates
|Crushed Stone (grade or number)||Size|
|#1||2″ to 4″ wide|
|#2||½″ to 1-1/2” wide|
|#5||1″ or less|
|#10 (Stone dust, rock, or gravel screenings)||⅛″ or smaller|
|#67||less than ¾″|
|#411 (Stone dust, rock, or gravel screenings)||¾” or smaller|
While these standards certainly define the product, it is not particularly helpful to the homeowner who needs the right material for a yard project. It would be like ordering a pizza by reading the list of ingredients. Besides, landscape material centers don’t typically call their product by a number.
Gravel doesn’t always refer to a natural product; stone is not always processed rock.
Now that you think you understand the difference between gravel and stone, I’m going to muddy-up the water here:
- “Crushed Stone” is a mechanically processed, free-draining aggregate. However, “Pea Stone” and “River Stone” naturally occurring; harvested from riverbeds or sifted from soil.
- “Crushed Gravel” is not a naturally occurring product – it is a compactible mixture of sand and stone that is the result of crushing and/or mechanically processing.
- The variety of local terminology like “processed gravel, road base,” or the basic, non-technical term “rock.”
So…what’s the easiest way to order gravel and stone?
By calling Groundhog Landscaping, of course! Since there seems to be no standard definition of these earth products, we here at Groundhog have made it very simple:
- “Gravel” is a mixture of sand and stone for compaction
- “Stone” is a free-draining aggregate (whether processed or naturally occurring.)
Now…wasn’t that easy?
If you are ready to order or still have questions, give our friendly office staff a call at (603) 437-4464 or check out our sand and gravel website page to view a description of each gravel and stone product that we offer.