Thallium
Thallium piece under vacuum in an ampule. Thallium is a very soft, malleable metal that can be cut with a knife at room temperature. It has a silvery luster when pure but will tarnish rapidly in air, and has to be stored under paraffin oil or under argon or vacuum in an ampoule; this sample contains a thin oxide layer. Thallium and its compounds are extremely toxic, and should be handled with great care.
Thallium
Thallium piece under vacuum in an ampule. Thallium is a very soft, malleable metal that can be cut with a knife at room temperature. It has a silvery luster when pure but will tarnish rapidly in air, and has to be stored under paraffin oil or under argon or vacuum in an ampoule; this sample contains a thin oxide layer. Thallium and its compounds are extremely toxic, and should be handled with great care.