30x30mm Cube Defective Cross Dichroic Prism RGB Combiner Splitter Glass Decor
Really pretty when set in the sunlight. Good buy.
Mine turned up with a fairly big chip out of the edge that extended about a 5th of the way down one side. It refracts sunlight all over the window sill it's sat on, So it's still quite a pretty effect, But it's a bit of a shame that it's got such a large chip out of it. :(