page_title: Phonolite
hierarchical_section_title: Phonolite
caption_attribution_description: Siim Sepp, 2005 Diameter of rock sample is app. 20 cm. Rock name is tinguaite (variety of phonolite) and it is from Sweden. Dark needle-like minerals are aegirine phenocrysts.
context_page_description: Phonolite is an uncommon extrusive rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic to porphyritic. Its intrusive equivalent is nepheline syenite.
  The name phonolite comes from the Ancient Greek meaning "sounding stone" because of the metallic sound it produces if an unfractured plate is hit; hence the English name clinkstone.
context_section_description: Phonolite is an uncommon extrusive rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic (fine-grain) to porphyritic (mixed fine- and coarse-grain). Its intrusive equivalent is nepheline syenite.
  The name phonolite comes from the Ancient Greek meaning "sounding stone" because of the metallic sound it produces if an unfractured plate is hit; hence the English name clinkstone.
caption: Aegirine phonolite. Dark prismatic minerals are aegirine phenocrysts.
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