http://cgi.ebay.com/big-13mm-baroque...QQcmdZViewItem
I know occasionally freshwater pearls do come in grey, but I'm just not sure if it's been treated. There are a few pearls with darker hue on the top, and there's just a hint of iridiscence.
http://cgi.ebay.com/stunning-11mm-pe...QQcmdZViewItem
This I'm certain is treated. I guess natural merely means they are pearls from a shell.
http://cgi.ebay.com/15mm-champagne-b...QQcmdZViewItem
Wonder how this comes up.