How to clean a diamond and regain its shine?

Iam a college going girl. i own a diamond ring, a penden, a braclet and a earing, so there is no exposure to heat, dust or smoke. but the diamond gets dark. it is real dimond and i do not have heat in my body. can you tell me how to clean it.|||I would just take it to the jewler and get it cleaned. I don't think its that much. like $50. I think its worth it to just go and get it done than try and figure out how to do it youself, and have the chance of screwing it up or it not working. hope I helped. good luck!|||toothpaste and an old toothbrush, but be carefull of the setting|||Try using a cheep toothpaste and a soft toothbrush. Rinse it thoroughly, this should help.|||Soda water works awesomely! I used to bartend and whenever I was done for the night I'd spray a little club soda on my ring and it looked like new again...actually worked better than the cleaner I bought at the jewelery store!|||Toothpaste will give it a great shine, brush it like you do your teeth.............|||How about cleaning with a toothbrush and toothpaste.If you are in College,you should know how to hit spell check.It is very hard to try to figure out what you're trying to say.....