Amphibolite: Description, Characteristics, and Other FAQs

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

What Is Amphibolite?

Amphibolite is a common metamorphic rock that forms through the high-grade metamorphism of mafic rocks.

It is characterized by the presence of amphibole minerals, typically hornblende and/or actinolite.

These minerals give amphibolite its typical dark greenish-black color.

Metamorphic means “changed form,” and amphibolite is a good example of how rocks can be changed.

Amphibolite forms when mafic rocks (rocks that are rich in iron and magnesium) are exposed to high temperatures and pressures.

Where Is Amphibolite Commonly Found?

Amphibolite is found in many areas of the world where ancient mafic rocks have undergone metamorphism.

For example, it is common in the Adirondack Mountains of New York, the Appalachian Mountains of North Carolina, and Scotland’s Highlands.

What Are Amphibolite’s Characteristics?

In addition to its dark color, amphibolite is characterized by a medium to coarse grain size.

It is also typically hard and durable, making it a popular choice for use in construction.

What Color Is Amphibolite?

Amphibolite typically has a dark greenish-black color.

What is the Moh’s Hardness Rating of Amphibolite?

Amphibolite has a Mohs hardness rating of 6-7.

Is Amphibolite Magnetic?

No, amphibolite is not magnetic.

Is Amphibolite a Rock or a Mineral?

Amphibolite is a rock. It forms through the metamorphism of mafic rocks and is characterized by the presence of amphibole minerals.

What Type of Rock Is Amphibolite?

Amphibolite is a metamorphic rock.

What Are the Uses of Amphibolite?

Amphibolite is commonly used in the construction industry, as it is an ideal material for a variety of applications.

For example, it is often used as flagstone, landscaping stone, and roofing shingles.

It is also a popular choice for use in countertops and other indoor applications.

Is Amphibolite Valuable?

The value of amphibolite varies depending on its location and quality.

In general, amphibolite is not considered to be a valuable rock.

Is Amphibolite Foliated or Non-foliated?

Amphibolite is non-foliated. Non-foliated means that it does not have a layered or flat structure.

Is Amphibolite Felsic or Mafic?

Amphibolite is mafic. Mafic means that it is rich in magnesium and iron.

Is Amphibolite Aphanitic or Phaneritic?

Amphibolite is phaneritic. Phaneritic means that the amphibolite grains are large enough to be seen with the naked eye.

Is Amphibolite Volcanic or Plutonic?

Amphibolite can be either volcanic or plutonic.

Amphibolite that forms from the metamorphism of igneous rocks is called plutonic amphibolite.

Amphibolite that forms from the metamorphism of sedimentary rocks is called volcanic amphibolite.

What is the Protolith of Amphibolite?

The protolith of amphibolite is mafic rock.

Is Amphibolite Intrusive or Extrusive?

Amphibolite is intrusive.

An intrusive rock is one that forms from solidified lava or magma below the Earth’s surface.

An extrusive rock is one that forms from solidified lava or magma above the Earth’s surface.

What is the Difference Between Amphibolite and Gneiss?

Amphibolite and gneiss are both metamorphic rocks.

The main difference between the two is that amphibolite is non-foliated, while gneiss is foliated.

Foliated rocks are those that have been formed through the process of metamorphism and have visible layers or bands.

Non-foliated rocks do not have visible layers or bands.

Is Amphibolite Magnetic?

No, amphibolite is not magnetic.

What Is Amphibolite’s Luster?

Amphibolite has a dull luster.

What is the Crystal System of Amphibolite?

The crystal system of amphibolite is monoclinic.

What is Amphibolite’s Streak?

Amphibolite’s streak is white.

What is Amphibolite’s Specific Gravity?

The specific gravity of amphibolite is 3.0.

What is Amphibolite’s Cleavage?

Amphibolite does not have cleavage.

What is Amphibolite’s Fracture?

Amphibolite has a conchoidal fracture.

A conchoidal fracture is a type of fracture that is curved or shell-like in shape.

What is Amphibolite’s Tenacity?

Amphibolite is brittle.

Is Amphibolite Radioactive?

No, amphibolite is not radioactive.

Can Amphibolite Scratch Glass?

Yes, amphibolite can scratch glass. Amphibolite is harder than glass (6-7 rating vs glass, which is generally around a 5).

Is Amphibolite a Hard Rock?

Yes, amphibolite is a hard rock.

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