Amphibolite

Main Elements:

Si, Al, Ca, Fe, Mg, O

Chemical Composition:

Similar to basalt: hornblende (amphibole), plagioclase feldspar, with minor quartz and biotite

Density:

2.9-3.2 g/cm³

Compressive Strength:

100-300 MPa

Melting Point:

Variable

Formation:

Forms when basalt or other mafic rocks are subjected to medium to high-grade metamorphism, causing the minerals to recrystallize into amphibole and plagioclase.

Composition:

Composed mainly of hornblende (amphibole mineral) and plagioclase feldspar, with minor amounts of quartz and biotite.

Types:

• Hornblende Amphibolite
• Garnet Amphibolite
• Eclogite (very high grade)

Etymology:

Named for its dominant mineral, amphibole, which comes from the Greek "amphibolos" meaning "ambiguous" or "doubtful".

Uses:

• Construction
• Decorative stone
• Railway ballast

Distribution:

Found worldwide in metamorphic terrains, especially in mountain ranges

Historical Use:

Used in construction and as decorative stone. Important for understanding Earth's tectonic processes.

Symbolism:

Represents transformation and Earth's deep processes

What is amphibolite used for?

Amphibolite is used in construction, decorative stone, and railway ballast due to its durability and attractive dark appearance.

How does amphibolite form?

Amphibolite forms when basalt or other mafic rocks are subjected to medium to high-grade metamorphism, recrystallizing into amphibole and plagioclase minerals.