Kindly, because rings live the roughest life in the box. Diamond at 10 on the Mohs hardness scale, sapphire at 9, and emerald at 7.5 to 8 all handle regular wear; warm water, mild soap, and a soft cloth clean them, and the pavé bands come off for the gym, the garden, and the pool. Stones set close together protect each other, one of stacking's quieter virtues.