Information needed about a diamond ring

[fyrestorm]

A little backstory on how I came in possession of the ring..
I was on a holiday with a couple of mates in Bulgaria and we found the ring on the seashore in about 150m inside the water. Went to a jewlery store the next day to ask about the authenticity of the finding and the guy told me the base of the ring is platinum, the chameleon is 18k gold with diamond stones also 18k. I doubt it, although he offered me $2k on the spot for it. Could you guys take a look at it and tell me what you think. What If I decide to sell it what documents or certificates shall I need or get. If so from where? I attach some photos of the ring.
http://i.imgur.com/h2hUy1p.jpg
http://i.imgur.com/n5WGbuD.jpg
http://i.imgur.com/G2RnPCl.jpg
http://i.imgur.com/DmhyRTi.jpg
http://i.imgur.com/FXVmEhG.jpg
http://i.imgur.com/GtrSNQ0.jpg
http://i.imgur.com/MEOuu8W.jpg
http://i.imgur.com/toeZjIM.jpg
http://i.imgur.com/2W5qyUR.jpg
http://i.imgur.com/NfRxvYT.jpg

 

[VRBeauty]

Based on your description, I suspect your best bet is to take it to some antique jewelry dealers or even an auction house to get an estimate of value. But - I'm intrigued. Could you post a picture?