As he had predicted, the silver heat they had found earlier was precious. In particular, it was an ancient artifact of the 'King of Beasts' relatives, something of little value to Minos and his group, but of great significance to the relatives of that legendary figure.
In exchange for the necklace, the previous Celestial had told the group about a part of the 'King Beasts' history that they still didn't know and told them where they could find the 'King Beasts' shrine. According to that Celestial, the old patriarch of the family had built a place with tough tests even for Celestials to pass, where they might have a better chance of finding what they were looking for.