Hot Tip on Thundereggs
Many lapidaries now heat
nodule and thunderegg halves under a heat lamp for a few minutes
before polishing with tin oxide or cerium oxide on felt. The
polish comes up almost instantly. Alternatives include putting
specimens in a 200degree oven until warm to the touch, or putting
them in a kettle full of hot water until they are warm. Dry
off excess water before polishing.