Salt is classified initially rich in silicon and aluminium (5)
I believe the answer is:
salic
'rich in silicon and aluminium' is the definition.
I can't tell whether this definition defines the answer.
'salt is classified initially' is the wordplay.
'salt' becomes 'sal' (I've seen this in other clues).
'initially' indicates taking the first letters.
The first letters of 'is classified' is 'ic'.
'sal'+'ic'='SALIC'
Can you help me to learn more?
(Other definitions for salic that I've seen before include "Law that excluded women" , "Law barring female succession" , "Is Cal strangely for a law that limits succession to males?" , "salty" , "Describes mineral rich in silicon and aluminium" .)