The example stone pictured above was cut from clear quartz. The outline is symmetrical 8-sided, but the finished stone looks more square shaped. Take your finished stone and look at it outdoors on a cloudy day. I think you will enjoy it. Be sure you have cleaned the stone of any finger prints.
Finger prints are disasterous for the brilliance.
The Star Cut was my first design and I cut it as my second stone. Now I have cut around 240 stones. I started faceting in 1987 when I bought a Raytech Shaw faceter.