The dark, mafic minerals in syenite tend to be amphibole minerals like hornblende. See its relation to the other plutonic rocks in the QAP classification diagram.
Being a plutonic rock, syenite has large crystals from its slow underground cooling. An extrusive rock of the same composition as syenite is called trachyte.
Syenite is named for the city of Syene, Egypt, where many ancient monuments are made of a light-colored stone like this.
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