Actinium Element Number 89 Ac

This is a fluorescent sample of autunite, an active Uranium ore. 1 ton of this material might contain 0.2 milligrams of Actinium. Actinium is not generally extracted from ores, but made in reactors for study. Like most people, except a lucky few, I will never see pure Actinium metal. I like the blue UV background of this photo, as pure Actinium is so radioactive the air around the metal will glow blue.

 Ac 89  metal D:10  MP:1922  BP: 5788  unstable AW:227 half life 21.773 years

Thorium Element Number 90 Th 

This is a  Thorite gemstone from Thailand. These are popular on EBay. This stone has a mild radio signature, and would not be wise to make jewlery with this stone.

These compounds of Thorium are somewhat exotic, and produced by a chemist in Canada. I never open vials of these materials, and keep these under lock and key. These emit alpha and beta radiation and must be handled in a serious manner. 

Th 90 metal  D:11.7  MP: 3348  BP:8650  Mohs: 3.0 unstable AW:232.0381   half life 1.405x10 to the 10th years.