syenite
- Scope note
- A phanoerocrystalline intrusive igneous rock composed mostly of alkaline feldspar with or without a smaller amount of plagioclase and without notable quartz or nepheline content. The term can also refer to a granite varietal, quarried in antiquity at Syrene in Upper Egypt, in which biotite is substituted for or accompanied by hornblende.
- Date of creation: 27-Jan-2025
Accepted term: 27-Jan-2025