Talk:Sivinski - Crystal Opal Emerald

This design has an intentional window. If you don't want the window, you'll need to change P1 to 44 degrees. In my opinion, a window is often good for Ethiopian crystal opal because if the stone is too bright it can wash out the color play. However I have seen beautiful opals cut both with and without a window and it's a matter of preference. If the color play is very bright almost anything will look good.

I like to polish with a Darkside with very little chrome oxide and light pressure at slow speeds. If you are getting new scratches at the polishing stage, try conditioning your polishing lap with a piece of corundum or quartz, then wet the lap well and wipe dry. Ethiopian opals can be brittle and little pieces of opal may be breaking off of facet edges and causing the damage. With some opals I'll condition after every tier, some never need it at all.