Bowl, BG mark - Barry Guppy

I bought this at auction.
I liked it but I can’t even be sure what is made from - lt was sold as a ceramic but I would just appreciate someone pointing me in a direction to identify it.

piece

You are 100% correct but I think you knew that - his mark which I didn’t post is on the bottom. I had no idea.
Is he collectible - I know he passed in 2013 but I can’t find any of his work for sale
Thank you NaomiM

I thought that NaomiM but it doesn’t look like they are.
Anyway it’s part of my collection and I am proud, thanks to you to say when anyone asks, “It’s by Barry Guppy, Princess Diana used to collect his work, as well as me!”

Hi! I used to rent a room from Barry and he had a pottery in Pimlico in Moreton Street. There is a photo online of Pimlico Pottery painted in red and black. The colours of an anarchist ! sadly the pottery and his home above were replaced by some flats. He made lots of different kinds of pots and also body sculptures which were commissioned by individuals and the sculptures are of the individual people. He rented out studios to students from Chelsea and various colleges. You can find his pottery for sale now and then and are very cheap for such excellent work. He moved to his parents home near the New Forest after they died and he had a studio as well. I have one of his splatter pots I call them in blue which I cherish.