Diabase vs Gabbro: What Are They, And What's The Difference?

Gabbro and diabase are two types of rocks that are very similar in appearance and composition that people often get confused about.

Gabbro is often considered to be a variety of diabase.

However, there are some key differences between these two types of rock.

Diabase vs Gabbro (Compared)

What is Diabase?

A diabase is a kind of basic intrusive igneous rock with low silica content and high iron content.

It belongs to the coarse-grained or fine-grained gabbro family.

The diabase is dark gray or black, with a natural luster.

The main ores are magnetite, ilmenite, chromite, and sulfides such as pyrrhotite and chalcopyrite.

The location of these minerals can be found in small patches or large scales like the whole rock body.

Diabase is the most common intrusive igneous rock in the crust and can be found on all continents.

In addition to being an important source of iron and magnesium, the diabase also contains trace elements such as titanium, chromium, manganese, zirconium, rare earth elements, etc.

These elements are important raw materials for various industrial sectors.

For example, ilmenite can be used to produce titanium dioxide; chromite can be used to produce chromium salts, etc.

How to Identify Diabase

The diabase can be identified by its dark coloration, fine grain size, and the presence of plagioclase feldspar and pyroxene.

The naked eye can generally tell if a rock is a diabase if it is fine-grained and has a dark color.

If the rock is coarse-grained, it may be difficult to determine if it is diabase or another type of rock.

A hand lens or other magnifying device can be helpful in this case.

The diabase typically has a greenish-black or grayish-black color, although some rocks may be more brown or green.

The rock may also have white spots or patches on its surface.

Where the Diabase is Found?

The diabases are found all over the world in a variety of locations.

Some notable places where diabase can be found include the Appalachian Mountains in the United States, the Ural Mountains in Russia, and parts of Scandinavia.

What are the physical properties of a diabase?

The physical properties of a diabase include:

-Color: The diabase typically has a dark color, ranging from greenish-black to grayish-black. Some rocks may be more brown or green. The rock may also have white spots or patches on its surface.

-Texture: Diabase is a fine-grained igneous rock. This means that the individual grains of rock is too small to be seen without a microscope.

-Hardness: Diabase is a very hard rock, with a Mohs hardness rating of 7.

-Specific Gravity: The specific gravity of the diabase is 2.8-3.0. This means that it is slightly heavier than other types of rock.

-Chemical Composition: Diabase is typically composed of plagioclase feldspar and pyroxene, with minor amounts of olivine or amphibole. It also contains small amounts of quartz and magnetite.

What is Diabase Used For?

Diabase is commonly used in construction, as it has great physical strength and durability.

It can be used to make paving stones, roofing tiles, foundations for buildings, and other types of construction materials.

Diabase is also commonly quarried for use in landscaping or as an ornamental stone.

Additionally, diabase is often mined for its metal ores, such as copper and nickel.

Overall, diabase is a versatile and useful rock that has played an important role in human civilization throughout history.

What is Gabbro?

Gabbro is another type of fine-grained rock that is similar to diabase.

Gabbro is a type of igneous rock that forms from the cooling and solidification of magma or lava.

Gabbro also consists mostly of plagioclase feldspar and pyroxene, though it may contain some olivine or amphibole as well.

Like diabase, gabbro often forms dikes or sills, though it can also be found in massive form.

Gabbro can be divided into two different types: fine-grained and coarse-grained gabbro.

Fine-grained gabbro has a more even grain size, while coarse-grained gabbro has larger crystals.

Gabbro is also sometimes classified into three different types: normal, porphyritic, and pegmatitic.

Porphyritic gabbros have large crystals in a matrix of smaller crystals, while pegmatitic gabbros have even larger crystals.

Gabbro is a dark-colored rock, but its exact color can vary depending on its composition.

It is usually black, greenish-black, or bluish-black.

How to Identify Gabbro?

Gabbro can be identified by its dark coloration, fine grain size, and the presence of plagioclase feldspar and pyroxene.

As with diabase, gabbro may also have white spots or patches on its surface.

The naked eye can usually tell if a rock is a gabbro if it is fine-grained and dark in color.

Some gabbros may have a lighter, more grayish hue compared to other dark igneous rocks.

Gabbro typically has a greenish-black or grayish-black color, although some rocks may be more brown.

A hand lens or other magnifying device can be helpful in determining the grain size of a rock.

Where is Gabbro Found?

It is generally found in the oceanic crust because it has low viscosity and high fluid content.

Gabbro is found in many different locations around the world.

Some of these include the Adirondack Mountains in New York, the Uinta Mountains in Utah, and Scotland.

Gabbro is also the main type of rock found in the oceanic crust.

What are the physical properties of Gabbro?

Gabbro is a dark, coarse-grained igneous rock that has a high density and typically contains some visible crystals.

This mineral has very low permeability and does not transmit fluids well, making it an important component of many types of bedrock.

Gabbro can be formed by the cooling of magma deep beneath the Earth’s surface or through the metamorphism of sedimentary rocks.

Some of the physical properties of gabbro include:

-Density (2.7 to 3.3 grams per cubic centimeter)

-Hardness (6 to 7 on the Mohs scale)

-Refractive index (1.87 to 1.90)

-Fracture characteristics (conchoidal)

-Color (usually dark gray or black, but may also have green or red layers)

-Chemical composition (~70% plagioclase feldspar, ~20% pyroxene minerals, and smaller amounts of other minerals like olivine or amphibole)

What is Gabbro used for?

Gabbro is a versatile rock that has been used for a variety of purposes throughout history.

It can be used in construction, as paving material, or as an ornamental stone.

Additionally, gabbro can be mined for its metal ores, such as copper and nickel.

Overall, gabbro is a versatile and useful rock that has played an important role in human civilization throughout history.

How are Diabase and Gabbro Similar?

As we mentioned before, diabase and gabbro are very similar in terms of appearance and composition.

Both rocks are dark in color and have a fine-grained texture.

Furthermore, both diabase and gabbro consist mostly of plagioclase, feldspar and pyroxene.

How are Diabase and Gabbro Different?

Though they are similar, there are some key differences between diabase and gabbro.

One of the most notable differences is that gabbro typically contains more olivine or amphibole than diabase.

Additionally, gabbro is usually found in mass form, while diabase typically forms dikes or sills.

Why Do People Confuse Diabase and Gabbro?

There are several reasons why people might confuse diabase and gabbro.

For one, both rocks are very similar in appearance, making it difficult to tell them apart.

Additionally, their compositions are also quite similar, which can further complicate things.

However, with a little bit of knowledge about these two types of rock, you should be able to easily distinguish between diabase and gabbro.

Conclusion

Overall, diabase and gabbro are very similar in composition and appearance, but there are some key differences.

Diabase is generally found as dikes and sills, while gabbro is usually an intrusion into the Earth’s crust.

Additionally, diabase has higher specific gravity and harder mineral content than gabbro.