Stone eggs are commonly polished in a rock tumbler. Also you may polish them on diamond grinding wheels, by hand using sandpaper or cut them with a saw and polish them on a flat lap.
The basic procedure is to tumble the rocks with progressively finer grits and polishes until the desired egg shape and shine is achieved. It may take 4 to 6 weeks to finish a batch.
Designed and dyed by nature herself, these polished natural stone eggs are the picture of elegance itself. Much more understated than the usual brightly-colored Easter eggs, natural stone eggs convey just the right combination of gravitas and playfulness.