NEW YORK – Jewellery comes in all shapes and sizes, but an icon comes only in one. That, for starters, is what makes an icon unique. Add popularity, and you’ve got the quixotic requirement for any iconic jewel: distinctive design, broad appeal. Some icons gain traction by dint of association, much like the Cartier panther with the Duchess of Windsor. Others are the happy result of critical mass. And some become the “gold standard” in a crowded field, such as the David Webb enamel animal bracelet.

The following are iconic standouts in the forthcoming Important Jewels sale, September 24-25.