Instead of, for instance, a test of ore? (5)
I believe the answer is:
assay
'test of ore?' is the definition.
'assay' can be an answer for 'test' (synonyms). I am unsure of the 'of ore?' bit.
'instead of for instance a' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'for instance' could be 'say' (both can be used to introduce an example) and 'say' is found in the answer.
A single letter 's' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for assay that I've seen before include "Examine (ore or alloy?)" , "Test (a metal or ore)" , "Test ore for content" , "metallurgical test" , "Test(ing) of a substance, such as precious metal" .)