Syenite
Plutonic feldspar-rich rock with little or no quartz and P/(A+P) 10–35% in the principal QAPF syenite field.
Language and route: Latin syenites from Greek/Roman toponym Syene. Latin syenites from Greek/Roman toponym Syene
Literal gloss: stone of Syene
The name and its history
Ancient *syenites* in Pliny; later petrographic usage associated with Werner; not a single 19th-century coinage · Classical usage; modern redefinition later
- What does the word literally mean?
- Literal naming sense: stone of Syene. Immediate language/formation: Latin syenites from Greek/Roman toponym Syene. The ancient toponym ultimately connects with Egyptian Swenet; do not equate Roman stone terminology with IUGS syenite.
- What did the original author mean?
- Ancient syenites was a quarry stone around Syene (present-day Aswan), much of which would now be classified as granite.
- Why was the name needed?
- Modern petrologists appropriated a well-known monumental-stone name when distinguishing quartz-poor feldspathic rocks.
- What evidence supported the original concept?
- Ancient quarry and monument descriptions followed later by mineralogical separation of quartz-rich and quartz-poor rocks.
- How has geology changed the concept?
- The name survives for a feldspar-dominated rock largely lacking quartz, not the principal Aswan stone referred to by Roman authors.
Further historical context
Ancient syenites was a quarry stone around Syene (present-day Aswan), much of which would now be classified as granite.
Modern petrologists appropriated a well-known monumental-stone name when distinguishing quartz-poor feldspathic rocks.
Ancient quarry and monument descriptions followed later by mineralogical separation of quartz-rich and quartz-poor rocks.
The name survives for a feldspar-dominated rock largely lacking quartz, not the principal Aswan stone referred to by Roman authors.
Related names
Granite · Monzonite · Orthoclase · Feldspar · QAPF classification
Sources
- Pliny, Natural History 36.13, stone of Syene (translation) — Ancient name and geographic referent
- BGS, Rock Classification Scheme — Modern descriptive rock-naming principles and definitions
- USGS, Lithologic classification of geologic map units — Modal definitions and named plutonic-rock categories
- IUGS / Le Maitre et al. (2002), Igneous Rocks: A Classification and Glossary of Terms, ch. 3 — Authoritative IUGS rock-name history and bibliographic attributions