Be wary of stirring a pan of any boiling substance with your rings on. Do not do the dishes in hot water while wearing your rings. Some gemstones do not do well if exposed to chemicals. Ammonia and acidic solutions like perfume, hairspray, lotions and even store bought jewelry cleaners, can ruin their surface - causing etching. Alcohol and acetone, which are in fingernail polish remover, will dissolve emeralds.
Chlorine can break down and pit gold alloys if exposed often enough.
It is wise to remove your jewelry while swimming or going in a Jacuzzi. The two gemstones that are most effected by chlorine and any other chemical are malachite and turquoise. All other stones that are dyed like jade and lapis should be kept away from chemicals too. Cleaning gemstones is important, especially if you wear them everyday. Cleaning them correctly to preserve them is a must.