How much can the diameter of cultured pearls in a hank vary from each other?

The diameter of cultured pearls in a hank can vary by 0.5 mm from one pearl to another. This variance is an accepted standard within the industry, as cultured pearls are natural organic gems produced by living mollusks. The slight differences in size can arise from factors such as the growth rate of the pearls and the conditions under which they were cultured.

The production of cultured pearls involves placing an irritant inside the mollusk, which then secretes layers of nacre around it. Since each mollusk can produce pearls under slightly different conditions and over varying time periods, a 0.5 mm variation accommodates these natural factors while still allowing for a visually appealing and uniform appearance when strung in a hank.

Values greater than 0.5 mm may pose challenges in maintaining a consistent look in jewelry, which is likely why this specific range is standard for cultured pearls.