By Duncan Miller
Here
is a quick and easy oval with a standard 1:1.30 proportion. It has a fully
conical pavilion, so you can spin a conical preform, stopping just short of
producing a point. This means you don’t have to change angles and mast height
when cutting the sixteen pavilion facets, which saves time and avoids mistakes.
This is a fully meet-point design that doesn’t require a preform, so it would
be good for a beginner’s first oval. It doesn’t work well in quartz or beryl,
so chose a suitable material with a higher refractive index, like corundum,
garnet or zircon.