Unmarked 60'/70s Lamp

Can someone help point me in the right direction for the maker of this?
I'm not even sure what exactly it's made from. It's heavy and has a bronze finish to it.

It also has an old brown bakelite plug which suggests it's late 60's or 70s.

height - 30cm
weight - 5kg

Thank you

I wonder if it's made from cement. Stoneware doesn't usually have bubbles like that

NaomiM wrote:I wonder if it's made from cement. Stoneware doesn't usually have bubbles like that

I had considered that and it would make sense by the weight of it.

It looks like a 1960s-70s design. Maybe commissioned by a lighting retailer from a sculptor, rather than a pottery manufacturer. Brutalist designs were popular back then

Is it black/dark grey? There is some stuff called ciment fondue that we used to cast with back in the 60s (a sculpture technique, as Naomi says), then add a finish
https://www.bathpotters.co.uk/ciment-fondue-grey/p959