Forget again to pick up some hard material (5)
I believe the answer is:
agate
'hard material' is the definition.
'agate' can be an answer for 'material' (agate is a kind of material). I'm unsure of the 'hard' bit.
'forget again to pick up some' is the wordplay.
'some' indicates the answer is hidden within the clue.
'to pick up' shows that the letters should be reversed in order.
'etaga' can be found hidden inside 'forget again'.
'etaga' back-to-front is 'AGATE'.
Can you help me to learn more?
(Other definitions for agate that I've seen before include "Banded ornamental stone" , "On the way" , "Variegated chalcedony" , "Old drama critic" , "rock with bands" .)