Ore analysis (5)
I believe the answer is:
assay
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ore analysis</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for assay that I've seen before include "Test gold" , "Test purity of precious metal" , "Analyse to find the properties" , "Test ore for content" , "Test, check" .)