February birthstone (8)
I believe the answer is:
amethyst
'february birthstone' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for amethyst that I've seen before include "One showing sparkling facets" , "Precious stone of purple quartz" , "Purplish gemstone" , "Purple quartz, used as a gemstone" , "A Middle East language" .)