Syenite

Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (< 5%). Some syenites contain larger proportions of mafic components and smaller amounts of felsic material than most granites; those are classed as being of intermediate composition. The volcanic equivalent of syenite is trachyte.

Group - plutonic.
Colour - variable but typically light coloured.
Texture - phaneritic (medium to coarse grained).
Mineral content - orthoclase, with lesser to minor plagioclase, minor mica, augite, hornblende, magnetite etc.
Silica (SiO 2) content - 60%-65%.
Uses - dimension stone for building facings, foyers etc (often preferred to granite due to its better fire-resistant qualities); can be used as aggregate in the building and roading industries.