Sham diamonds for queen in welcoming party (9)

I believe the answer is:

deception

'sham' is the definition.
(thesaurus)

I can't explain the rest of the clue.

(Other definitions for deception that I've seen before include "Fraud" , "Illusion" , "Duplicity" , "Trick" .)

I've seen this clue in The Times.

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