Mineral from Oriental caves (4)
I believe the answer is:
talc
'mineral' is the definition.
(talc is a kind of mineral)
'from oriental caves' is the wordplay.
'from' says the answer is hidden in the clue.
'TALC' is hidden in the letters of 'oriental caves'.
(Other definitions for talc that I've seen before include "Drier" , "Soft stuff" , "Bathroom dusting powder" , "In brief, popular body powder" , "It is used to absorb moisture" .)