Figures half queens are in possession of great formal beauty (10)
I believe the answer is:
statuesque
'are in possession of great formal beauty' is the definition.
The answer and definition are different parts of speech. However, past participle verbs and adjectives occasionally define each other.
'figures half queens' is the wordplay.
'figures' becomes 'statues' (statue is a kind of figure).
'half' suggests halving the letters.
'queens' halved is 'que'.
'statues'+'que'='STATUESQUE'
Can you help me to learn more?
(Other definitions for statuesque that I've seen before include "(Of a woman) tall and dignified" , "imposing" .)