Syenites

Syenites: intrusive rocks composed mainly of Alkaline Feldspars, either Sodic or Potassic, with smaller amounts of Plagioclase and Mafic minerals. The texture is granular holocrystalline, sometimes porphyritic. The volcanic equivalents of Syenites are Trachytes.

sieniti
(Photo: Siim Sepp/Wikimedia Commons, License CC-BY-SA-3.0)

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