syenite
Concise Oxford English Dictionary © 2008 Oxford University Press:
syenite /ˈsʌɪənʌɪt/
▶noun Geology a coarse-grained grey igneous rock composed typically of alkali feldspar and hornblende.
– derivatives
syenitic adjective.
syenitic adjective.
– origin C18: from Fr. syénite, from L. Syenites (lapis) ‘(stone) of Syene’, Greek name of Aswan in Egypt.
'syenite' also found in these Oxford entries:

