The exquisite diamond and South Sea pearl necklace was crafted by Garrard, the crown jeweller at the time. Interestingly, the design of the necklace incorporated input from Diana herself.

A single South Sea pearl can cost $1,500, and a necklace can reach over $200,000. So, how are these pearls grown? And what makes them so expensive? More from Retail South Sea pearls are the ...