Henry takes it with English rock salt (6)

I believe the answer is:

halite

'rock salt' is the definition.
('halite' can be a synonym of 'rock salt')

'henry takes it with english' is the wordplay.
'henry' becomes 'hal'.
'takes' says to put letters next to each other.
'with' is a charade indicator (letters next to each other).
'english' becomes 'e' (abbreviation).
'hal'+'it'+'e'='HALITE'

(Another definition for halite that I've seen is " Rock salt".)

I've seen this clue in The Telegraph.

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