November's birthstone (5)
I believe the answer is:
topaz
'november's birthstone' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for topaz that I've seen before include "Silicate gemstone" , "Yellowish-brown gemstone" , "Precious stone - dark yellow colour" , "White/colourless mineral used as a gemstone" , "valuable item" .)