No guise about some rock (7)
I believe the answer is:
igneous
'some rock' is the definition.
(igneous rock is a kind of rock)
'no guise about' is the wordplay.
'about' indicates anagramming the letters.
'no'+'guise'='noguise'
'noguise' anagrammed gives 'IGNEOUS'.
(Other definitions for igneous that I've seen before include "Originally molten (rock)" , "Type of rock with molten origin" , "(Rock) of volcanic origin" , "Formed by intense heat" , "(Of rocks) formed from lava or magma" .)