The typical simple crystal of zircon is a tetragonal prism terminated with four sided pyramids at each end. The prism may be lacking and the crystal can look octahedral. More complex crystals have faces of a less steeply inclined prism that taper the terminations. Also a secondary prism may truncate the primary prism by cutting off its edges and producing an octagonal cross-section through the crystal. As you can see, zircon crystals can go from a very simple crystal to a rather complexly faceted form.
Color is brown, red, yellow, green, blue, black, and colorless.
Luster is adamantine. Transparency crystals are transparent to translucent. Cleavage indistinct in two directions, prismatic. 7.5 Specific Gravity is 4.6-4.7 Streak white Associated Minerals albite , biotite , garnets , xenotime and monazite . Best Field Indicators are crystal habit, hardness, luster and density.