My hottest materials are uranothorite specimens from Bancroft, Canada. I collected them from an old pegmatite mine. I have from the mine are a specimen of betafite which contains a lot of uranium, autunite which is a uranium phosphate, and uraninite. There are at least 70 thorium and uranium minerals. They may or may not have a large amount of thorium or uranium in them.
Vaseline glass contains a small amount of uranium and fluoresces brilliantly under black light.
A number of naturally occurring radioactive minerals fluoresce under black light - such as autunite. Some radioactive minerals show no fluorescence. Emissions from small amounts of thorium disrupt the structure of zircons and several other minerals. It can be useful in the home lab or workshop, too. Next up in the seminar will be a discussion of Cleavage by Al O.- getting us back on track.