Gems that may appear strange in a new setting (7)

I believe the answer is:

garnets

I'm a little stuck... Click here to teach me more about this clue!

'gems' is the definition.
(garnet is a kind of gem)

'may appear strange in a new setting' is the wordplay.
'strange' anagrams to 'GARNETS'.
However, I am unsure how this is indicated.

'that' is the link.

Can you help me to learn more?

(Other definitions for garnets that I've seen before include "Strange turn of the gemstones" , "Stones" .)

I've seen this clue in The Globe and Mail.

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