Wingspan 3-4 mm.
One of the world's smallest moths; some examples having a wingspan of only 3mm!
There are two or three generations in the British Isles, with adults on the wing between April and July and larvae feeding between May and October. The moths have brassy inner forewings, a silvery fascia and purplish beyond.
The larval mine is very distinctive. Feeding on sheep's sorrel (Rumex acetosella) or common sorrel (R. acetosae), the larva mines in a tight spiral, which turns bright red, and later moves away in an irregular gallery.