What does the cryptic crossword clue "Place stone in such a way that it's like a pearl? (10)" mean?

The wordplay uses an anagram. anagram of PLACE + STONE = OPALESCENT The answer is OPALESCENT.

Place stone in such a way that it's like a pearl? (10)

Daily Mail Cryptic #16274 | 13 Across | 2020-03-18 flower