I found them browsing on Etsy through the 'shop local' feature, where I was looking at recently listed items from sellers in Melbourne and Sydney. There were so many beautiful designs to choose from, but I fell in love with these, plus I figured they would go very nicely with our dinner set. They've been gracing the dining table on most nights since they arrived.
They're made from upcycled vintage teacups collected by the lovely Ruth at Twilight Spells in Sydney and are filled with clean-burning soy wax. Check out the others in her shop - they are too pretty for words, and you can choose your own fragrance for the wax (or leave them unscented). I decided on honeydew melon for these ones, largely (I confess) because the cups themselves were so green; they smell delicious, sweet and fruity without being overpowering.
I generally prefer to drink out of my vintage teacups (of which I have a slowly increasing collection - another post about that to follow shortly), but this is such a terrific idea I wish I'd thought of it first... Thanks Ruth, I will be checking in at your shop regularly!