Violet gem (8)
I believe the answer is:
amethyst
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">violet gem</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 amethyst that I've seen before include "One showing sparkling facets" , "Purplish gemstone" , "Precious stone of purple quartz" , "Violet gemstone" , "Semiprecious stone of violet or purple quartz" .)