Why can crushed opal rods be hard to work with?

Home Frequently Asked Questions (FAQ) Why can crushed opal rods be hard to work with?

Like any glass that has an additive, it become more difficult to work with.  Also, opal is not 100% compatible with borosilicate.  An opal can cause a crack many years down the road.  This is why Steve rarely uses them, but they are sexy.

Also, if a blower is not good, it will burn out the opal, making it just white flakes.