Definition of syenite in US English:

syenite

noun

Geology
  • A coarse-grained gray igneous rock composed mainly of alkali feldspar and ferromagnesian minerals such as hornblende.

    • ‘A violet, coarse-grained, porphyritic quartz syenite, which makes up large parts of the pluton, was collected for dating.’
    • ‘The southern Zomba area consists mainly of syenite surrounded by a periphery of alkaline granite.’
    • ‘The selective removal of these minerals resulted in a change of the composition of the magma to one near that of the rock syenite.’
    • ‘The province is also endowed with other non-traditional minerals including nickel, feldspar, emerald, limestone, granite, amethyst, sodalite and syenite.’
    • ‘Originally, the syenite was barged, until about 1949 when it was hauled by truck 24 miles to the CNR at Lakefield, which distance was only slightly farther than the CPR had to build.’

Origin

Late 18th century: from French syénite, from Latin Syenites (lapis) ‘(stone) of Syene’ (from Greek Suēnē Aswan in Egypt).

Pronunciation

syenite

/ˈsaɪəˌnaɪt//ˈsīəˌnīt/