### Clue: Die long time after Durbeyfield girl (7)
### Answer: TESSERA 
 ### Explanation: Definition: Die
 ERA(a long period of time) **placed after**(after) TESS(short name for the main character, Teresa Durbeyfield, in Thomas Hardy's novel "Tess of the d'Urbervilles").
Defn: As a singular of dice, a small cube, possibly used in constructing a mosaic.
Tess is described as an anti-heroine, cf. 12 across.