I've never seen this design in Dartington Studio before - do you have an image of the etched mark?
(otherwise, my guts are suspecting a possible shifting of a label...)
I "discovered" Dartington Studio glass in a sale in a local upmarket homewares shop, circa 2000, and thought it to be of high quality and a very good price (in the sale) so I bought some Alchemy - as did my brother, who also bought some of the pieces with the crackle design in white over colour. I started watching out for the new designs coming out, having tracked them down via the Stuart Factory shop in Crieff.
So I know of the Alchemy, the crackle, then there was stuff with gold foil, followed by the optic ribbed swirly stuff, and cranberry stuff coloured with gold then the Studio went bust.
This, if it is Dartington, is a new one on me!