Ore of lead
I believe the answer is:
galena
'ore of lead' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for galena that I've seen before include "Commonest ore of lead - Angle "A" (anag)" , "Lead sulphide mineral" , "Len, GAA produces lead sulphide" , "Angela (anag) - ore producing lead" .)