Wingspan 9-14 mm.
This species is quite an early flyer, being on the wing in April and May, and despite being generally diurnal, is often found in light-traps at night.
The moths have metallic golden wings, lightly speckled with purplish or blue tiny spots. The relatively uncommon form fastuosella is much more richly marked with purple spots or striations.
The larvae feed internally on leaves of oak (Quercus), and create a distinctive 'blotch mine'.
It is common throughout the whole of Britain except the very north of Scotland.