What are amphibole minerals?

Amphiboles are a major group of hydrous minerals that occur in a wide range of rock types. They occur predominantly in metamorphic and igneous rocks of the Earth’s crust and upper mantle. Two metamorphic facies are defined by their characteristic amphiboles.

What is hornblende used for?

Its primary use might be as a mineral specimen. However, hornblende is the most abundant mineral in a rock known as amphibolite which has a large number of uses. It is crushed and used for highway construction and as railroad ballast. It is cut for use as dimension stone.

What kind silicate is hornblende?

amphibole
Hornblende is a member of the amphibole group of more complex silicates, in which the tetrahedra are linked to form a continuous chain twice the width of the pyroxene chains. For this reason they are often referred to as double chain silicates.

How is hornblende mineral formed?

It occurs as a detrital heavy mineral in sedimentary rocks. It forms in a number of gneissic rocks formed at moderate grades of metamorphism. Amphibolites are common metamorphic rocks consisting in large part of dark amphibole.

What is amphibole used for?

It is used as paving stones and as a veneer or facing on buildings (both for interior and exterior use). It is also used as crushed stone for the usual crushed stone applications such as road and railroad bed construction. In this application it is used locally, near the source of the amphibolite.

Why is amphibole important?

Amphiboles have a wide range of chemical substitutions. Their chemical composition and general characteristics are very similar to the pyroxene group. They are an important constituent in a variety of plutonic and volcanic igneous rocks. Igneous amphiboles intermediate in composition are referred to as hornblende.

What’s another name for hornblende?

Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole.

Where is amphibole found?

Amphiboles are found principally in metamorphic and igneous rocks. They occur in many metamorphic rocks, especially those derived from mafic igneous rocks (those containing dark-coloured ferromagnesian minerals) and siliceous dolomites.

What is the difference between tourmaline and hornblende?

Tourmaline is distinguished from biotite and hornblende by the absence of cleavage, the presence of striated prisms, and (for hornblende) parallel extinction. Lighter colored tourmalines can be confused with topaz, apatite or corundum, but can be distinguished by certain optical properties.

What rocks contain hornblende?

Hornblende is a common constituent of many igneous and metamorphic rocks such as granite, syenite, diorite, gabbro, basalt, andesite, gneiss, and schist.

Where is amphibole commonly found on Earth?

General considerations. Amphiboles are found principally in metamorphic and igneous rocks. They occur in many metamorphic rocks, especially those derived from mafic igneous rocks (those containing dark-coloured ferromagnesian minerals) and siliceous dolomites.