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

The most common amphibole, hornblende, is usually black; however, they come in a variety of colors depending on their chemical composition.

From Textbooks • Jan. 1, 2017

This effect is especially strong if the new minerals are platy like mica or elongated like amphibole.

From Textbooks • Jan. 1, 2015

In amphibole structures, the silica tetrahedra are linked in a double chain that has an oxygen-to- silicon ratio lower than that of pyroxene, and hence still fewer cations are necessary to balance the charge.

From Textbooks • Jan. 1, 2015

The results of this process are illustrated in Figure 5.10, which shows a granitic rock in which some of the biotite and amphibole have been altered to form the iron oxide mineral limonite.

From Textbooks • Jan. 1, 2015

Pargasite, p�r′ga-sīt, n. a dark-green crystallised variety of amphibole or hornblende.

From Chambers's Twentieth Century Dictionary (part 3 of 4: N-R) by Various