Size: When other value factors are equal, larger pearls are rarer and more valuable than smaller pearls of the same type. Shape: Round is the most difficult shape to culture, making it the rarest ...

The most expensive pearl ever sold was Marie Antoinette's pendant. It sold for $32 million in a 2018 auction. But what is it that makes pearls so expensive? Marie Antoinette's pearl was part of a ...

The rarest of pearls include those which are naturally blue, pink, green, or purple. The most valuable pearls have high ...

Yet rarely in life does upheaval change everything. Hugh Burkitt reflects on his career as chief executive of The Marketing Society and passes on his seven most valuable pearls of wisdom. Thirteen ...

Natural pearls are harder to find ... Black opal costs from $1,000 a carat to tens of thousands of dollars. The most valuable black opal features bright red stone against a very black base.