Peridotite: Description, Characteristics, and Other FAQs

In this article, you’ll obtain answers to common questions about Peridotite.

What Is Peridotite?

Peridotite is a type of ultramafic rock that typically consists of olivine and pyroxene.

Ultramafic means that Peridotite has a very low silica content, and is thus high in magnesium.

Where Does Peridotite Get It’s Name?

It’s named after the gemstone peridot, which is green in color and composed of the mineral olivine.

Where Is Peridotite Found?

Peridotite is found in Earth’s mantle, as well as in meteorites.

It’s also a significant component in the oceanic crust.

Because Peridotite is found in the mantle, it’s found all over the world.

How Is Peridotite Formed?

Peridotite is thought to be formed when magma rises to the Earth’s surface and solidifies.

This can happen through a process called mantle plumes, which are column-like upwellings of magma in the Earth’s mantle.

Mantle plumes can rise for hundreds of kilometers, and as they rise, the pressure on the magma decreases.

This decrease in pressure allows gas bubbles to form, and as the magma cools, the gas bubbles are trapped.

This process can result in a rock that is up to 90% Peridotite.

What Are the Physical Characteristics of Peridotite?

Peridotite typically has a greenish-brown color, but can also be yellow, red, or gray.

The texture of Peridotite can be anywhere from fine-grained to coarse-grained.

What Is The Moh’s Hardness of Peridotite?

The Moh’s hardness of Peridotite is 6.5-7.

What Are the Chemical Characteristics of Peridotite?

As mentioned earlier, Peridotite has a very low silica content.

It’s also high in magnesium and iron.

What Are The Uses of Peridotite?

Peridotite is sometimes used as a gemstone, but it’s not as popular as other gemstones such as diamonds or rubies.

It can also be used in the production of magnesium and iron.

Is Peridotite a Rock or a Mineral?

Peridotite is a rock, because it’s composed of multiple minerals.

To be considered a mineral, a specimen must be composed of a single element or compound.

What Are the Minerals in Peridotite?

The most common minerals found in Peridotite are olivine and pyroxene.

It may also be composed of minerals such as amphibole, biotite, and feldspar.

Is Peridotite Igneous, Sedimentary, or Metamorphic?

Peridotite is igneous because it’s formed from the solidification of magma.

Sedimentary rocks are formed from the deposition of sediment, and metamorphic rocks are formed from the alteration of preexisting rocks.

Is Peridotite Foliated or Non-foliated?

Peridotite is non-foliated because it does not have a layered or banded structure.

Is Peridotite Felsic or Mafic?

Peridotite is mafic because it has a high magnesium and iron content.

Felsic rocks are rich in silica, while mafic rocks are low in silica.

Rocks that are rich in silica are usually light in color, while those that are low in silica are usually dark in color.

Is Peridotite Aphanitic or Phaneritic?

Peridotite is aphanitic because it has a fine-grained texture.

Phaneritic rocks have a coarse-grained texture.

Is Peridotite Volcanic or Plutonic?

Peridotite can be either volcanic or plutonic.

Volcanic Peridotite is formed when magma rises to the surface and solidifies.

Plutonic Peridotite is formed when magma cools and crystallizes below the surface.

Is Peridotite Intrusive or Extrusive?

Peridotite can be either intrusive or extrusive.

Intrusive Peridotite is formed when magma cools and crystallizes below the surface.

Extrusive Peridotite is formed when magma rises to the surface and solidifies.

Is Peridotite Valuable?

Peridotite is not as valuable as other gemstones, such as diamonds or rubies.

However, it is still often used as a gemstone, and in decor.

A small piece of peridotite usually costs around $5.

What Is The Streak Color of Peridotite?

The streak color of peridotite is white.

What is the Luster of Peridotite?

The luster of peridotite can be vitreous, pearly, or resinous.

What is the Diaphaneity of Peridotite?

Peridotite is translucent to opaque.

What is the Cleavage of Peridotite?

Peridotite does not have a cleavage.

What is the Fracture of Peridotite?

Peridotite has an irregular fracture.

What is the Grain Size of Peridotite?

The grain size of peridotite can be anywhere from fine-grained to coarse-grained.

What is the Specific Gravity of Peridotite?

The specific gravity of peridotite is 3.3-3.4.

Is Peridotite Magnetic?

Peridotite is not magnetic.

What is Peridotite’s Tenacity?

Peridotite’s tenacity is brittle.

Is Peridotite Fast or Slow Cooling?

Peridotite is slow cooling.

Is Peridotite Granite?

No, peridotite is not granite.

Granite is a type of igneous rock that is rich in silica, while peridotite is a mafic rock that is low in silica.

Is Peridotite Porphyritic?

No, peridotite is not porphyritic.

Porphyritic rocks are those that contain large crystals (phenocrysts) embedded in a fine-grained matrix.

Peridotite is aphanitic, meaning it has a fine-grained texture without any crystals.

What Is The Meaning of Peridotite?

The name peridotite comes from the Greek word peridona, which means “giving plenty.”

This is likely a reference to the abundance of the mineral olivine in peridotite.

People use peridotite to encourage abundance and luck.

It is also said to promote emotional balance and well-being.

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