Some thing from a bygone era. 1B3GT & a 1S2 EHT rectifiers from B&W valve TV era. Also a solidstate AEG TV18-2MT EHT 18Kv rectifer which was suplied as a kit to replace the 1S2 valve. These were for the EHT for the picture tube.

 

Photo2; My all time favorite weird electronic parts! These are bright pink ceramic very high voltage TO-3 insulators. They are VERY hard and make cool "shiiick" sounds when rubbed together, and best of all they feel ice cold when you first pick them up. It must be some very highly thermally conductive ceramic, they feel much colder then say glass or any type of stone that i have felt. I think 1970's, from bigscreen TVs.

Hi RB, these are almost certainly berylium oxide. Wash your hands after touching them and if you ever break or chip them make sure you don't cut yourself or it won't heal properly. It's nasty stuff but generally safe in the bulk ceramic form, just don't every try grinding them.