The September Birthstone: Sapphire

The September birthstone is the stunning and enigmatic sapphire. Traditionally signifying nobility, faithfulness and truth, today the gemstone is known for its unique blue hue and symbol of status.

A Gem Fit for Royalty

kate middleton sapphire ring

Sapphires have long been associated with royalty, appearing on the robes of dignitaries and clergy throughout history. From Helen of Troy to Queen Victoria and Apollo to Pope Innocent III, sapphires have traditionally served as a mark of power. Perhaps the most famous modern example is Kate Middleton, who wears the 18-carat sapphire ring once worn by her mother-in-law, Princess Diana. It is considered one of the most well-known heirloom gemstone engagement rings in history.

Sapphire Specs

blue sapphire

The sapphire falls in the corundum family, which is the same gemstone group as the ruby. In fact, these stones represent two different hues of the same mineral. Corundum gems are known for their density and compactness. With a rating of 9, sapphires rank as the third hardest mineral on the Mohs scale after diamonds (10) and moissanite (9.5). Some sapphires appear with asterisms, which are star-like shapes caused by tiny inclusions. These distinct stones are known as star sapphires and are truly spectacular to behold.

A Curious Case of Color

Sapphires are commonly recognized for their deep blue hue, however they also occur naturally in a rainbow of other colors. This is due to a phenomenon called pleochroism, which accounts for different colors seen in different crystal directions. These variations can include shades of:

  • Green
  • Orange
  • Pink
  • Purple
  • Yellow

Red is the only color in which sapphires do not occur naturally.

Famous Sapphire Stones

The most expensive sapphire gemstone ever recorded is known as “The Blue Belle of Asia.” The jaw-dropping gemstone, an untreated Ceylon sapphire dripping from a diamond tassel pendant necklace, is cushion-cut and weighs in at an astounding 392.52 carats. The Blue Belle sold for over $17 million at auction at Christie’s Geneva in November 2014, setting a world record for the highest price ever paid for a sapphire at auction. The buyer is reported to be extremely private and remains anonymous to this day. Other famous sapphires include:

The Logan Sapphire. Image sourced from
  • The Logan Sapphire: one of the largest sapphires in the world at 422.99 carats, the gem was given to the Smithsonian in 1960 by Mrs. John A. Logan.
  • The Richelieu Sapphires: a pair of 26.66-carat and 20.88-carat sapphire earrings once given to Odile de Richelieu as a wedding gift, selling for $8.3 million at auction at Sotheby’s Geneva in November 2013.
  • The Star of Bombay: a 182-carat star sapphire from Sri Lanka on display at the Smithsonian, once given to silent film star Mary Pickford by her husband.
  • The Rockefeller Sapphire: a rare, rectangular-cut Burmese sapphire once owned by the Rockefeller family, 62 carats in weight and selling for over $3 million at auction at Christie’s NYC.
  • Bismarck Sapphire Necklace: a 98.6-carat stone from Sri Lanka cast in a diamond and platinum Cartier-designed necklace, given to the Smithsonian in 1967 by Countess Mona Von Bismarck.
  • Maria Alexandrovna’s Sapphire Brooch: purchased by Russian Emperor Alexander II at the Great London Exhibition of 1862 for his wife, Empress Maria Alexandrovna, the 260.37-carat stone is known for its unusual blend of cut, clarity, size and color.

While sapphires have long been associated with important historical figures, nowadays one only needs to be born in September to harness the deep blue gemstone’s mystique.

Learn more at Ritani’s Gemstone Education center, or shop our selection of sapphire rings and jewelry now.