Some Contemporaries for this "Slags & Swirls Saturday" The first 2 are signed Geoffrey Beetem Dichroic Lutz Types & the third is an unsigned and unknown Auger type, all are around 1&1/2"
No was never mine, I remember when you bought it though, I'm the one that directed you to the site last year .... Jeff & Tammy ( https://oldraremarbles.com/ ) are only about 50 mi. from me
Warm soapy water and a medium bristle brush (maybe a couple hours soaking) never any harsh chemicals or "Hot" water, don't want the glass to react in a bad way, steel wool if needed.