Anger about the first stone (6)
I believe the answer is:
garnet
'stone' is the definition.
(precious stone)
'anger about the first' is the wordplay.
'about' indicates an anagram.
'the first' becomes 't' (1st letter of 'the').
'anger' anagrammed gives 'garne'.
'garne'+'t'='GARNET'
(Other definitions for garnet that I've seen before include "Hard glassy mineral used as a gemstone" , "Semi-precious stone of deep transparent red" , "Semi-precious stone of argent type" , "Glassy red, yellow or green gemstone" , "Deep red gem stone" .)