Mineral chart enters pigment (5)

I believe the answer is:

ochre

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'pigment' is the definition.
(ochre is a colour)

'mineral chart enters' is the wordplay.
'mineral' becomes 'ore' (ore is a kind of mineral).
'chart' becomes 'ch' (I can't justify this - if you can you should believe this answer much more).
'enters' means one lot of letters goes inside another.
'ore' enclosing 'ch' is 'OCHRE'.

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(Other definitions for ochre that I've seen before include "Light yellow-brown colour" , "An orangey pigment" , "Yellow/brown pigment" , "Yellowish-brown or red pigment" , "Brown" .)

I've seen this clue in The Telegraph.

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