French 18k Gold Ruby 'August 21st' Calendar Pendant Chain Necklace

This late 20th century 18k yellow gold August calendar pendant necklace, designed as a rectangular calendar page for Août, the French word for August. The pendant is engraved with a monthly calendar grid and set with a ruby marking August 21st, likely intended as a personal birthdate or commemorative jewel. The back is engraved with Gr. O and Rh. –, and the pendant is stamped with a French eagle head hallmark for 18k gold. The pendant measures 1 3/4 inches in length by 1 inch in width and weighs 12 grams. It is currently paired with a later 18k yellow gold chain, stamped Italy and 18k, measuring 31 inches in length and weighing 4.8 grams. The necklace weighs 16.8 grams in total. There is surface wear is present, consistent with age and prior wear.