| 1. | Andesites contain quartz and dacites-rhyodacites contain sanidine megacrysts.
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| 2. | Sanidine is stable at the highest temperatures, and microcline at the lowest.
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| 3. | Sanidine phenocrysts and augite ( or enstatite ) are found in some samples.
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| 4. | Sanidine and high albite constitute a solid solution series with intermediate compositions termed anorthoclase.
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| 5. | Phenocrysts include biotite, Si magmas, while higher Si magmas also contain sanidine.
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| 6. | The Rosada ignimbrite's main minerals are biotite, quartz, plagioclase and sanidine.
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| 7. | They are of trachytic appearance, containing phenocysts of sanidine, leucite, augite and biotite.
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| 8. | Other minerals occurring in the rock include sanidine, andradite, fassaite, leucite and hauyne.
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| 9. | The Pliocene ignimbrites contain biotite, ilmenite, magnetite, plagioclase, quartz, sanidine and sometimes amphibole.
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| 10. | They are rich in leucite, but contain also some sanidine and often much nepheline with hauyne or nosean.
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