It is from the very short-lived Dartington Studio range.
I found some pieces in a posh furniture and home decor shop, (from new), around 2002, and took a very serious interest, they were such wonderful bits of glass.
What I managed to find out, at the time, was that this Studio range was based around using classical designs, and making their own take on them, using old-fashioned methods and colours.
The "Alchemy" design was a "take" on Monart "Cloissonne" design, but using gold foil as well (absolutely beautiful pieces I'll get an image of mine when the light's better). My brother was here in Dundee at the time, and I dragged him along to the shop where he bought a few of the style in the link posted above, which is another "take" on Monart Cloissonne, but the design flattened into the casing. I also ordered a large charger in a deep red, with this foil pattern on it, a "take" on the old Venetian style gold foiled pieces, from the Stuart shop in Crieff, as they were carrying the Dartington studio ranges around that time.
Following these patterns, they launched into making "cranberry" glass, with swirly, optic ribbing, using gold to make the correct ruby colour.
However, it turned out that it was getting incredibly expensive to make these pieces, and folk were simply not prepared to pay the premium they cost, and the Studio folded. (I don't know exactly when, but it was shortly after I "discovered" it).