When one thinks of stone, its use in famous buildings probably first comes to mind, but few people probably realize that stone in some form enters our lives probably a hundred times even before we leave the house each day.

Five main groups of uses can be identified:

• Building and decorative stone – stone used for its resistance to weather or its aesthetic appeal – walls and decorative purposes. Buildings, walls, paving slabs.
• Aggregates – stone used for its strong physical properties – crushed and sorted into various sizes for use in concrete, coated with bitumen to make asphalt or used ‘dry’ as bulk fill in construction. Mostly used in roads, concrete and building products.
• Industrial purposes – limestone can be used for its chemical (mainly alkaline) properties as calcium carbonate (CaCO3) in farming and manufacturing industry.
• Lime burning (calcining) – limestone when heated to a high temperature breaks down into lime (calcium oxide) and carbon dioxide gas. It can then be used as a more powerful alkali than limestone (see above) or used as a cement with sand, to make mortar, or as a soil improver in agriculture.
• Cement – if limestone (or its variety chalk) is mixed with clay or sandstone before firing, it can produce Portland cement which when mixed with aggregate makes concrete.

Crushed stone is a heavy commodity of relatively low value. Therefore, it is more economical to use the product in a construction setting close to a population center that is also close to the mining source in order to limit the cost of transportation. Crushed stone is used mostly as aggregate for road construction and maintenance. It is also used for making cement, lime, chemical applications, and in agriculture.

Bulk crushed granite ranges between $38 and $75 per yard or $24 to $50 per ton. For folks who don’t need this much, smaller quantities are sold at local home improvement stores. But expect to pay more, at least $5 for .5 cubic feet of crushed stones. However, the convenience may make it worthwhile for you. The most common types of rock processed into crushed stone include limestone, dolomite, granite, and traprock. Smaller amounts of marble, slate, sandstone, quartzite, and volcanic cinder are also used as construction aggregates.

One of the most popular styles, crushed stones are typically around 1 inch in length and can be made from a variety of stone types (granite is common). They’re removed from the ground as whole stones and put through a crusher to break them into small, angular chunks of stone.

Crushed stone has many applications, but it’s frequently used as a mulch replacement. These stones look great around most types of plants and, since no one would be walking on them, their jagged edges aren’t a factor. Also, crushed stone makes a great base material to place under patios and walkways. These stones promote drainage, allowing water to run through the walkway and into the soil underneath.

Today, the only building stone quarried on Mendip is Doulting Stone (Jurassic Inferior Oolite). In the past, small quantities of other materials have been worked as decorative stone and building stone, but the total quantity produced in any year in the past has probably never exceeded a few thousand tons and currently is only a few hundred tons.

River rock describes stones of a wide variety of materials removed from a riverbed. Due to water currents and erosion, these stones are smooth and rounded. They come in a wide range of sizes, from under an inch to more than a foot wide, with just as varied of a color palette.

Because river rocks are so smooth and rounded, they are more comfortable underfoot for a walkway. Keep in mind that it’s important to use small river rocks for a walkway, as larger ones are more likely to move or twist as a foot land on them. These rocks also are an attractive way to border a walkway. And since there aren’t any jagged edges to snag a foot, people who venture off the path aren’t likely to get hurt.

One area where using river rocks can pose a problem is in garden beds. Because of their rounded contours, they will leave substantial, irregularly shaped gaps between the stones. Because of their rounded shape, the rocks will leave large irregular gaps between stones, which creates openings for weeds to sprout. This is mostly true of larger river rocks, as smaller rocks don’t form big gaps. River rocks cost between $50 and $160 per ton in bulk. With .5-cubic feet bags costing $5 each (a total of around $270 per yard), buying in bulk is almost half as expensive.

This type is composed of small, rounded rocks that are roughly the size of a pea or bean. There’s a mix of individual stones of different varieties and colors. The rounded shape of pea gravel makes it beneficial for walkways, dog runs, patios, or even playgrounds. It can also help with drainage for landscaping projects or act as mulch in flower beds and gardens. Since these stones are on the small side, there is minimal opportunity for gaps between the stones to prevent weed growth. The cost for a bulk ton of pea gravel ranges between $10 and $50. For a .5-cubic foot bag of pea gravel from the home improvement store, expect to pay around $4 each.

As one might guess from the name, lava rock is made of the molten discharge from volcanoes. It comes in both red and black colors, and it’s generally very lightweight compared to other landscaping rocks. Irregular and very rough in shape, these will add texture and depth to garden beds that many other stone types can’t replicate. One thing to note is that lava rock isn’t suitable for walkways or patios due to its rough and uneven texture. However, it’s great in place of mulch and provides a unique look. It’s also suitable for drainage, especially since the individual rocks are porous, but large-scale drainage projects can be expensive. Lava rock costs between $80 and $240 per ton, or $50 to $180 per cubic yard. If purchased from a home improvement store, 6-pound bags can cost around $8 each.

Flagstone is a category of stone, not a specific stone material. It can consist of sandstone, slate, bluestone, limestone, or quartzite. What makes these materials flagstone is that they are shaped like flat slabs. This shape is particularly suitable for building walkways and patios. Since the stones are extremely flat and level, they can be laid down in such a way that there are very few variations in height between the stones. Due to the sizes of the individual stones, flagstone is generally sold by the pallet, and each pallet weighs around 1 ton. One pallet can cost around $200 and $550 each.

Fieldstones are generally large, round rocks found during excavating or farming, which means they can be made of different types of stones. Fieldstones are suitable for many tasks. If used properly, they can work as retaining walls, lining walkways, or even stone wall fences. Depending on their size and shape, they can function as seats around a bonfire or stepping-stones in a walkway. When stacking these stones, it may be necessary to use mortar, but dry stacking without mortar is also doable. Fieldstones are sold by weight, and they can range from $80 to $180 per ton. It’s possible to order them from a home improvement store, but prices will vary.

A general description of a boulder is any stone that’s too large for one person to pick up alone, for example, it could be a stone that is at least 2 feet wide. Boulders make for excellent retaining walls and rustic seating arrangements. They’re also helpful for creating tiered yards with separate planting areas. Because these are so heavy, it’s a good idea to have a design plan in mind as you don’t want to move them around to find the right spot. Boulders cost between $100 and $600 per ton, and they’re typically only available from stone suppliers or excavation companies. Delivery and installation may or may not be part of the price, so it’s important to clarify before purchasing.

Let our team be your convenient bulk materials resource for that finishing touch to complete your outdoor vision. Contact Nick Lofferdo, Bulk Products Manager.