Analyze, as ore (5)
I believe the answer is:
assay
'analyze as ore' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for assay that I've seen before include "Put to the proof" , "Test purity of precious metal" , "Test ore for value" , "Examine chemicals" , "Test (a metal or ore)" .)