I didn't click on the link but I can tell you that the 4C s are impossible to tell from a picture. The logging of the picture Nd monitor coloring will affect te color- and unless you have a magnified photo of the atone clarity can be anythig if it's eyeclean. youbreally need an accurate appraisal in order to swyeine the 4Cs.
Since we do not know the ring size, I'd say the carat weight is probably between 0.7 and 1.5 ct.
Since the skin tone looks pretty accurate the white balance of the camera was not way off so I'd guess the color grade may be between D and J.
The camera focused on the side diamonds, not on the main diamond.
The diamond being blurred makes it impossible to guess the clarity or even the cut, but I'd guess it is somewhere between flawless and I1.
I2 or I3 would probably be detectable, even in that pic.
It could be a princess or a cushion or a radiant or other cut.
The pic does tell us it's not a marquise, triangle, heart, or a pear.
How well it is cut could vary from the best to the worst possible.
Even if it was the best photograph in the world you still can't grade diamonds by pics, though at least the cut could be identified.
Based on the very wide range of the 4Cs that the pic suggests, I'd guess the value to be somewhere between $2,000 and $50,000 depending on if it was offered for sale new in a high end store on Fifth Ave. in Manhattan, or used and offered for sale by you to a pawn shop in Detroit.