It's not a pear-shaped diamond. It's paste. Which sounds gross, but in the late 1700s, paste was a remarkable new technology. Leaded glass, originally in a liquidy "paste" form, was cast, cut and faceted just like gemstones, without the rarity or difficulty of mining diamonds and transporting them from distant lands. These, the earliest of synthetic gems, were typically set in silver, often in dish-shaped mounts designed maximize sparkle. Foil was sandwiched behind the stone to reflect light outward, and sometimes this foil was colored. Here, someone chose the most vivid Marie Antoinette pink imaginable. The colored paste is the star, while the seven rose cut diamonds are just supporting players.
. MATERIALS: silver, 7 rose cut diamonds, pear-shaped pink paste, new 14k gold chain
AGE: c. 1780
CONDITION: Very good - small scratch on table facet of the paste, old repair mark on the back side
SIZE: 1 1/2" x 1/2"