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orthopyroxene
/ ˌɔːθəʊpaɪˈrɒksiːn /
noun
- a member of the pyroxene group of minerals having an orthorhombic crystal structure, such as enstatite and hypersthene
orthopyroxene
/ ôr′thə-pī-rŏk′sēn′ /
- Any variety of the mineral pyroxene that crystallizes in the orthorhombic system and contains no calcium and little or no aluminum. Enstatite is an orthopyroxene.
Example Sentences
Some orthopyroxene crystals, for instance, have a magnesium-rich core surrounded by an iron-rich rim; others have an iron-rich core and a magnesium-rich rim.
The outer rim of an orthopyroxene crystal, she says, represents the most recent stage of crystal formation and typically grew just months before the crystal’s emergence in volcanic ejecta.
In a study appearing in the May 25 issue of Science, the researchers report that crystals of the silicate mineral orthopyroxene from 1980 and from subsequent eruptions trace various injections of magma, as well as other chemical changes, within the bowels of the volcano.
"Previously it's been reported that iron-rich rims on orthopyroxene are due to changes in the content of the magma, so it makes sense that if we've got degassing or fluxion of water or CO2 through the system, we may get more iron-rich rims," she says.
She and colleagues studied a mineral crystal called orthopyroxene from Mount St. Helens in Washington.
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