Pearls an organic gemstone. Natural pearls form in a mollusk around an irritant. The mollusk creates layers of nacre around the irritant. With cultureld pearls a bead or piece of tissue is deliberately inserted in the mollusk. This mollusk is coating this insertion with nacre. Unfortunately you hardly find any natural pearls anymore. And if this mother of nature beauty is found it's very expensive.
Pearls are for centuries loved by royalty. You can't blame them the beautiful pearl is a great match with every other gemstone.