special poltsyrene finish

[welsh brickie]

Hi all
I am trying to find information on a material I have seen years ago,It looked like cereal,It was like a polystyrene with resin that is applied with a trowel like plaster.it was used in a bathroom and was striking to look at.
But I cannot find the name of the product or if its still used,has anyone seen it or heard of it please
thanks