Colored pearls



How can I tell if a pearl strand is artificially colored? I have read that dye and a kind of radiation is used. I want black pearls, but Tahitian pearls are a little out of my price range. But I want natural black color. Black akayo pearls look the best to me, but I especially do not want radiation treated.

Thank you.
If you are looking for true black pearls you must go with the Tahitians. There is a saying in China about black Akoya pearls. They are about as natural as a blond Chinese girl. They do not exist. The darkest I have seen is a grey-blue. And this is straight out of the oyster.
I know that radiation treatment does sound a bit scary, but I would not avoid them at all costs. The pearls will not be radioactive ;) Akoya pearls that are radiation treated tend to be quite a bit darker, and have a very consistent color, so many times I feel they are nicer than those that are dye-treated.