Hi Robert,
It is entirely clear crystal - although it does have a blueish/grey tint to it. There's a beautifully polished pontil, quite shallow, oval shape, quite large, 2.5 inches long x 1.5 inches wide.
Years ago this had a sibling, same size and colour but it had some plumage.
I've taken a photo in natural light which I think shows it better.
Thanks for your reply