Go outside on a clear day and hold them up in the sun’s glare. That should do it for the shine part.

Actually, I wiped mine with plain water, window cleaner and the old standby [shutter] spit. Diamonds are the hardest mineral, so I’m not to worried. I still have yet to try the all house favorite, vinegar.

Fill a glass with some vinegar and drop your rings in overnight.

ammonia. A good diamond will sparkle no matter what. You shouldn’t have to ever clean a diamond, just the setting, a complicated setting can get grimy and make the whole ring look not so great. try brushing it with rubbing alcohol or ammonia

1 cup water
2 tablespoons liquid dish detergent
1 tablespoon ammonia

Put in a jar, let sit for 10 minutes, agitate, then remove jewelry and rinse. A jarful should last several months. The dish detergent removes the gunk from the setting. Use a soft brush, if needed.

I have always used ammonia and water.

Years ago, my jeweler told me how they cleaned jewelry. Take equal parts of water & ammonia & put it in a baby food jar. Heat it in the microwave until it boils. Then drop your jewelry in it & swirl it around. You can just see the crap floating out of them. Let it set about an hour & then scrub them with dish soap. I’ve used this method for years & years.

I heard once to use Windex and a toothbrush and water to rinse. Blow dry (hair dryer) on low. Never tried. I like @jbfletcherfan‘s response. Sounds reliable.