Q：How are pearls formed?

A：The formation of pearls is due to a biological process known as the self-defense mechanism of pearl oysters. When foreign objects (such as grains of sand, parasites, etc. enter the soft tissue of pearl oysters, the mollusks secrete a substance called nacre to envelop these foreign objects, reducing irritation and protecting themselves. This nacre, primarily composed of calcium carbonate and organic substances, gradually accumulates in layers to form pearls. The longer the time, the thicker the layers of nacre accumulate, resulting in larger and more beautiful pearls. This process typically takes several years or even longer, and factors such as the species of mollusk, environmental conditions, and other factors can influence the final characteristics of the pearls.