hornblende

American  

[hawrn-blend] / ˈhɔrnˌblɛnd /

noun

1. a dark-green to black mineral of the amphibole group, calcium magnesium iron and hydroxyl aluminosilicate.

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hornblende British  

/ ˈhɔːnˌblɛnd /

noun

1. a black or greenish-black mineral of the amphibole group, found in igneous and metamorphic rocks. Composition: calcium magnesium iron sodium aluminium aluminosilicate. General formula: (Ca,Na) 2.3 (Mg,Fe,Al) 5 Si 6 (Si,Al) 2 O 22 (OH) 2

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hornblende Scientific  

/ hôrn′blĕnd′ /

1. A common, green to black mineral of the amphibole group. It has a variable composition and occurs in monoclinic crystals with a hexagonal cross-section, in fibrous forms, or in granular forms. Hornblende is found in many metamorphic and igneous rocks. Chemical formula: (Ca,Na) _2-3 (Mg,Fe,Al) ₅ (Al,Si) ₈ O ₂₂ (OH) ₂₂ .

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Other Word Forms

• hornblendic adjective

Etymology

Origin of hornblende

From German, dating back to 1760–70; horn, blende

Example Sentences

Other minerals, with hornblende being a good example, are longer in one direction, linear like a pencil or a needle, rather than a planar-shaped book.

From Textbooks • Jan. 1, 2017

Diorite is identifiable by it’s Dalmatian-like appearance of black hornblende and biotite and white plagioclase feldspar.

From Textbooks • Jan. 1, 2017

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

Biotite and hornblende are also commonly used for K-Ar dating.

From Textbooks • Jan. 1, 2015

The huge blocks of brown ironstone, however, which are found near the summit, in the hollow path by which it is customary to ascend, owe their origin to the decomposition of the hornblende.

From Narrative of the Circumnavigation of the Globe by the Austrian Frigate Novara, Volume I (Commodore B. Von Wullerstorf-Urbair,) Undertaken by Order of the Imperial Government in the Years 1857, 1858, & 1859, Under the Immediate Auspices of His I. and R. Highness the Archduke Ferdinand Maximilian, Commander-In-Chief of the Austrian Navy. by Scherzer, Karl Ritter von