How do I clean a diamond ring at home without ruining prongs?

Safest home method: warm water, a drop of Dawn, 20 minutes soak, soft toothbrush on the underside, pat dry. Skip toothpaste, skip paper towels (they scratch). Do this every 2-4 weeks and your ring will look new.

Ultrasonic cleaners are safe for diamonds, sapphires, rubies, and plain gold bands. They are NOT safe for pearls, opals, emeralds, turquoise, or any fracture-filled stones. If you are unsure, use warm soapy water instead.

A diamond certificate (GIA/IGI) grades the stone itself. An appraisal values the whole piece for insurance. They serve different purposes. You need both: the cert when buying, the appraisal when insuring.

A wedding band on during the gym is usually fine, but skip it for heavy lifting or pull-ups. Bars and weights bend rings and snap prongs. Lifting can also crush a stone against metal. I take mine off for gym and keep it in a locker.