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.

---

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

---

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 .

---

Etymology

Origin of amphibole

1600–10; < French < Late Latin amphibolus amphibolous

Example Sentences

The metamorphic rock, amphibolite, is primarily composed of amphibole minerals.

From Textbooks • Jan. 1, 2017

Examples of minerals are feldspar, quartz, mica, halite, calcite, and amphibole.

From Textbooks • Jan. 1, 2015

To be more specific, felsic rocks typically have biotite and/or amphibole; intermediate rocks have amphibole and, in some cases, pyroxene; and mafic rocks have pyroxene and, in some cases, olivine.

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

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