Unnaturally, Darwin takes gloss initially off diamonds in the design studio (7,6)

'the design studio' is the definition.

'unnaturally darwin takes gloss initially off diamonds' is the wordplay.
'unnaturally' is an anagram indicator (I've seen this in other clues).
'takes' is a charade indicator (letters next to each other).
'initially' indicates taking the first letters.
'diamonds' becomes 'ice' (I've seen this before**).
The initial letter of 'gloss' is 'g'.
'darwin' with letters rearranged gives 'drawin'.
'drawin'+'g'+'off'+'ice'='DRAWING OFFICE'

'in' is the link.