cordierite

American  

[kawr-dee-uh-rahyt] / ˈkɔr di əˌraɪt /

noun

1. a strongly dichroic blue mineral consisting of a silicate of magnesium, aluminum, and iron: common in metamorphic rocks.

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cordierite British  

/ ˈkɔːdɪəˌraɪt /

noun

1. Also called: dichroite.   iolite.  a grey or violet-blue dichroic mineral that consists of magnesium aluminium iron silicate in orthorhombic crystalline form and is found in metamorphic rocks. Formula: (Mg,Fe) 2 AL 4 Si 5 O 18 .nH 2 O

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cordierite Scientific  

/ kôr′dē-ə-rīt′ /

1. A light-blue to dark-blue or gray orthorhombic mineral. Cordierite is a silicate of magnesium, aluminum, and sometimes iron, and is found in granites and in metamorphic rocks that form under relatively low-pressure conditions. Chemical formula: (Mg,Fe) ₂ Al ₄ Si ₅ O ₁₈ .

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Etymology

Origin of cordierite

1805–15; named after Pierre L. A. Cordier (1777–1861), French geologist; see -ite ¹

Example Sentences

Thus, he reasoned, a Viking could have located the sun by rotating a chunk of cordierite until it turned dark blue.

From Time Magazine Archive

Among these may be mentioned cordierite and sillimanite gneisses, andalusite and kyanite mica schists, and those schistose calc silicate rocks which are known as cipolins.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 6 "Home, Daniel" to "Hortensius, Quintus" by Various

The sedimentary schists into which these rocks have been intruded may show contact alteration by the development of such minerals as cordierite, andalusite and sillimanite.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 2 "Gloss" to "Gordon, Charles George" by Various

There is also a long list of accessory minerals which are present in gneisses with more or less frequency, but not invariably, as garnet, sillimanite, cordierite, graphite and graphitoid, epidote, calcite, orthite, tourmaline and andalusite.

From Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 2 "Gloss" to "Gordon, Charles George" by Various

In the rocks of this group cordierite also occurs, not rarely, and may have the outlines of imperfect hexagonal prisms which are divided up into six sectors when seen in polarized light.

From Encyclopaedia Britannica, 11th Edition, Volume 13, Slice 6 "Home, Daniel" to "Hortensius, Quintus" by Various