World's Largest Star Sapphire Was Deemed Worthless and Used as a Doorstop for 9 Years

September's birthstone is sapphire, so today we present a little history about a famous sapphire that nearly lost its chance to shine.

When the world's largest gem-quality star sapphire gem was found in 1938 by 12-year-old Roy Spencer in Queensland, Australia, the boy's dad dismissed the stone as an enormous black crystal and threw it aside. Although the palm-sized stone weighed an incredible 1,156 carats, it spent the next nine years languishing as a doorstop in the Spencer family home.

The dad, Harry, was a pioneering miner of the central Queensland gem fields, but apparently didn't realize that sapphires could present themselves in this unique black color. Eventually, Harry, learned that sapphires did, in fact, come in nearly every color of the rainbow (except for red, which is called "ruby"). The struggling miner realized that the family's doorstop could be worth a small fortune if the right buyer could be found.

In 1947, gemstone aficionados soon learned that the massive gem-quality black sapphire was for sale. This got the attention of Armenian-born jeweler Harry Kazanjian, who traveled from Los Angeles to Queensland to make a deal. Kazanjian agreed to pay $18,000 (about $185,000 in today's dollars).

Kazanjian studied his new purchase for two months before deciding how it would be cut. Convinced there was an asterism hidden within the rough stone, Kazanjian cut the stone as an oval cabochon, sacrificing 423 carats of material, in order to reveal a six-pointed star. Star sapphires contain intersecting needle-like inclusions that cause the appearance of a star-shaped pattern when viewed with a single overhead light source.

Kazanjian's investment and cutting expertise paid off. The estimated value of the expertly cut 733-carat black star sapphire was $1 million in the year 1949.

Named "The Black Star of Queensland," the humble gemstone that spent nine years as a doorstop is now set majestically as a pendant framed by 35 diamonds. It's valued at about $80 million and is considered one of the most famous sapphires in the world.