amphibole

American  

[am-fuh-bohl] / ˈæm fəˌboʊl /

noun

Mineralogy.

1. any of a complex group of hydrous silicate minerals, containing chiefly calcium, magnesium, sodium, iron, and aluminum, and including hornblende, tremolite, asbestos, etc., occurring as important constituents of many rocks.

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amphibole British  

/ ˈæmfɪˌbəʊl /

noun

1. any of a large group of minerals consisting of the silicates of calcium, iron, magnesium, sodium, and aluminium, usually in the form of long slender dark-coloured crystals. Members of the group, including hornblende, actinolite, and tremolite, are common constituents of igneous rocks

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amphibole Scientific  

/ ăm′fə-bōl′ /

1. Any of a large group of usually dark minerals composed of a silicate joined to various metals, such as magnesium, iron, calcium or sodium. Amphiboles occur as columnar or fibrous prismatic crystals in igneous and metamorphic rocks. Most are monoclinic, but some are orthorhombic. Hornblende, actinolite and glaucophane are amphiboles. Chemical formula: (Mg,Fe,Ca,Na) _2-3 (Mg,Fe,Al) ₅ (Si,Al) ₈ O ₂₂ OH ₂ .

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Etymology

Origin of amphibole

1600–10; < French < Late Latin amphibolus amphibolous

Example Sentences

A bright green variety of amphibole occurring usually in fibrous or columnar masses.

From Project Gutenberg

HORNBLENDE, an important member of the amphibole group of rock-forming minerals.

From Project Gutenberg

In these the minerals have a parallel arrangement, the felspars are often broken down by pressure into a mosaic of irregular grains, while greenish fibrous or bladed amphibole takes the place of pyroxene and olivine.

From Project Gutenberg

The asbestos formerly used in the arts was generally a fibrous form of some kind of amphibole, like tremolite, or anthophyllite, though occasionally perhaps a pyroxene.

From Project Gutenberg

It is a blue fibrous mineral belonging to the amphibole group and closely related to riebeckite; chemically it is an iron sodium silicate.

From Project Gutenberg