Fire (gemstone)
(Other definitions for agate that I've seen before include "Hard stone with concentric bands of colour" , "marble" , "Onyx" , "Quartz gem" , "Precious stone" .)
(Other definitions for opal that I've seen before include "Delicately-coloured gem" , "Semi-precious stone of b;uish white colour" , "Milky iridescent stone" , "Precious stuff" , "Translucent gem" .)