What is "zircon syenite"

Zircon \Zir"con\, n. [F., the same word as jargon. See Jargon a variety of zircon.]

1. (Min.) A mineral consisting predominantly of zirconium silicate ( Zr2SiO4) occurring in tetragonal crystals, usually of a brown or gray color. It consists of silica and zirconia. A red variety, used as a gem, is called hyacinth. Colorless, pale-yellow or smoky-brown varieties from Ceylon are called jargon.

2. an imitation gemstone made of cubic zirconia.

   Zircon syenite, a coarse-grained syenite containing zircon crystals and often also el[ae]olite. It is largely developed in Southern Norway.