Diorite Rock – Uses, Facts & Properties – All You Need to Know

Diorite Rock – Uses, Facts & Properties – All You Need to Know

Mar 28, 2023

If you are like most customers going to buy natural stones with any knowledge to differentiate igneous rock from the sedimentary rock, the supplier or stockiest might introduce you to diorite as granite stone.

In the dimension stone industry, any rock with visible interlocking grains of feldspar, the granite is common. However, diorite is falling in between the granite and basalt based on the compositions and properties.

Of course, diorite and andesite have the same mineral content and occur in the same areas. The difference is grain size and cooling rate during the rock formation process. 

  • Slow cooling of diorite results into coarse grain size due to large crystals formation with more ion transport. 
  • Rapid cooling of andesite, which is forming closer to the surface, results in fine-grained textured rocks.

Diorite Formation:

Diorite is intrusive igneous rock. So, when the partial melting of an oceanic plate takes place, the resulting basaltic magma rises and intrudes on the rocky continental plate. 

If granitic magma or rocks are present there, the mixing of basaltic and granitic magmas are taking place under the continental crust/plate. 

Thereby, the mixing produces a melt, which is remaining as the intermediate of granite and basalt. The melt crystallizes below the earth’s surface, but above the deep granite layer, and it is termed as Diorite. 

Due to a contrasting mixture of black & white mineral grains, the Salt & Paper appearance takes place and becomes the identification clue for the diorite rocks.

Formation Location of Diorite:

 Diorites found as large intrusions, as the plutons, which are a gigantic mass of rocks. 

  1. Diorite formation also takes place as small rock bodies called sills, which are mostly horizontal tubular bodies inserted between other existing rock types.
  2. Similarly, diorites occur as dikes, which are mostly vertical tubular bodies form due to the injection of magma in the fissures present within the mass of existing rocks.

Reserves of Diorite:

The occurrence of diorite is not common but found almost in all contents of the planet.

Eastern Continent


  • Egypt


  • Leicestershire and Aberdeen shire in the United Kingdom
  • Thuringia and Saxony in Germany
  • Sondrio in Italy
  • Northeastern Turkey
  • Central Sweden
  • Finland | Romania 

Western Continent

North America:

  • USA 

South America: 

  • Argentina | Bolivia
  • Chile | Colombia
  • Ecuador | Peru

Oceania Continent

  • The Darren range of New Zealand, including Northland, Coromandel Peninsula, west Nelson area, Fiordland, Stewart Island.
  • The Andes Mountains of Western Australia

Composition of Diorite:

  • Diorite is sodium-rich due to the high content of plagioclase.
  • It has hornblende, biotite, and pyroxene minerals as minor content.
  • Diorite has traces of other minerals found in other igneous rocks. The presence of quartz and feldspar gives it a contrasting black & white appearance. If it has too much quartz content, it becomes quartz diorite.

Physical Properties of Diorite:

Parameters  Values
Hardness  4 to 7
Grain size  Medium to coarse 
Compressive strength  225.00 N/mm2
Toughness  2.1
Density 2.8-3 g/cm3
Specific gravity  2.8 to 3
Porosity Less porous 
Luster Shiny
Streak Bluish black 
Resistance Heat, pressure, and wear 

Textural Properties of Diorite:

Parameters  Values
Colors Black, Brown, Light to Dark Grey, and White.
Appearance  Shiny 
Durability  Durable with water, scratch, stain, wind, and acid resistance.

Applications of Diorite:


Diorite as A Base Material in The Construction Industry:

2-6mm 2 to 6mm size Diorite Aggregates:
  • Dark gray colored micro size chipping of diorite is ideal for roughcast.
  • It useful in a permeable drainage system when used with 10-63mm & 10-20mm sizes. The mixture compacts lesser than the sand alone.
4-10mm 4 to 10mm size Diorite Aggregates:
  • It is an excellent choice as a decorative stone.
  • You can apply it on or along the walking paths, driveways, & patios, as well as any hard-standing areas in your landscape.
10-20mm 10 to 20mm size Diorite Aggregates:It is highly useful in decorative purposes in the Japanize style of gardens.

10 to 63mm size Diorite Aggregates:

  • Useful as sub-base in the permeable drainage system, parking lots, pedestrian plaza, and public places.

Diorite Uses in The Dimension Stone Industry:

Diorite is a sturdy natural stone. So, it easily accepts the various stone surface finishes and texture treatments. You cut diorite rocks into any size and shape of the dimension stone-like tiles, slabs, stone bricks, stone blocks/cubes, and stepping stones.

Applications of diorite stones are found in the interior as well as exterior spaces of the buildings.

Exterior Applications of Diorites:

  • Exclusively designed outdoor patios.
  • Walking paths in your landscape.
  • Roadside paths with basalt border.
  • Diorites have a long history as cobblestones to create public & private roads.
  • Exterior paving to decorate your façade.

Like other dimensional stones, diorite stone slabs are an excellent choice to create outdoor utilities, including siting benches, tables, seats on top of dwarf retaining walls.

Diorites in the Interior Designing Industry

Interior Applications of Diorites:

We know about the natural beauty of granites well. Now, diorites are nearby cousins of granites in many respects. You can create glossy stone tiles or slabs and use in the interior decoration as well as utilities like a floor, wall cladding, and even a reception desk from a whole cube!

Diorites in Interior Kitchen Designing:

Like granites, the diorite stones are good candidates for kitchen countertops, cabinet, and tabletops, as well as dining tabletops.

Artistic Uses of Diorites in Decoration, Sculpture, and Outdoor Features

  • Diorites found in Pottery & Decoration Industry
  • Diorites used in Sculpture Making Industry
  • Diorites in GemStone Industry

Apart from these, diorite cabochon “Pink Marshmallow Stone” found in Australia seems to beautify thanks to large size pink feldspar crystals.

Find Diorite Natural Stones in Your Neighborhood:

World of Stones USA is a hub of natural stones with high-quality products at competitive market rates. You have room for selection out of a huge stock and varieties. Let’s explore the treasure online or offline!


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