Short story about powdered mineral (4)
I believe the answer is:
talc
'powdered mineral' is the definition.
(I've seen this before)
'short story about' is the wordplay.
'short' means to remove the last letter.
'story' becomes 'tale' ('tale' can be a synonym of 'story').
'about' becomes 'c' (abbreviation for 'circa'**).
'tale' with its last letter removed is 'tal'.
'tal'+'c'='TALC'
(Other definitions for talc that I've seen before include "Soft mineral; powder" , "It is used to absorb moisture" , "Softest substance in Mohs scale of hardness" , "Fragrant powder" , "Cosmetic powder" .)