The Black Star of Queensland: Unveiling the Mysteries of the Largest Black Star Sapphire

The Name Black Star of Queensland reflects both the nature of the gemstone and its place of origin. The 733-carat Black Star of Queensland is the largest black star sapphire in the world, and was discovered in the 1930s in the Anakie Sapphire fields of the Rubyvale area in the State of Queensland, in northeastern Australia.

Characteristics of the stone

The 733-carat Black Star sapphire is an oval-shaped gemstone cut as a cabochon like all other star sapphires, but the rays or legs of the star are not as long as the normal blue star sapphire and other colored star sapphires, which extend from the center to the girdle. The rays in blue star sapphires are also fairly thin and narrow and tapers towards the girdle. On the other hand, the rays of this black star sapphire are shorter and thicker extending about half way from the center towards the girdle. The rays are not of equal length; some are shorter than the others. However, the center of the star is much bigger and brighter than the normal star sapphires. The appearance of the bright six-rayed star in a totally black background is amazingly beautiful. The beauty of the stone is further enhanced by its white gold setting in which the large black stone is surrounded by a row of 35 pear-shaped smaller white diamonds. The color contrast is indeed breathtaking. Like all other star sapphires the star moves with changing angles of illumination and observation.

The black star sapphire like all other sapphires belong to the group of minerals known as corundum, a crystalline form of aluminum oxide (Al2O3), that is after diamond, the hardest known natural substance, with a hardness of 9 on the mohs scale. Corundum crystallizes in the hexagonal system, resulting in pyramidal or rounded barrel shapes. Like diamonds, corundum was formed billions of years ago deep inside the earth, below the earth's crust and in the mantle, under conditions of high temperature and pressure. Subsequently, when the magma cooled down it formed igneous rock deposits and the corundum was incorporated in these deposits. Later as the igneous rocks were transformed into sedimentary and metamorphic rocks the corundum was also incorporated into these rocks. Continuous weathering and erosion of the rocks over millions of years released the corundum crystals which were washed down the hills and deposited in the flood pains of rivers as alluvial deposits.

In the pure state corundum is colorless, like pure diamonds which are also colorless. However the incorporation of trace quantities of impurities in the crystal structure of corundum, causes a wide range of colors, which includes all the colors of the rainbow such as violet, indigo, blue, green, yellow, orange, red and pink. Others colors include gray, brown and black. All colors of corundum except red are known as sapphires. Red corundum is known as ruby. The common color in sapphires is blue. Other colors such as violet, green, yellow, orange and pink are known as fancy colored sapphires. The blue color in sapphire is caused by trace quantities of iron and titanium. Green color is caused by traces of nickel, orange color by traces of chromium and iron.

Accidental discovery of the rough stone and its use as a door stop

The enormous gemstone was discovered accidentally in 1938 by a young boy of around 12 years named Roy Spencer when he was playing around in the claim where his father used to prospect for sapphires, known as the Reward claim, which lies within the Anakie Sapphire fields in the Rubyvale area, in the State of Queensland. The Anakie Sapphire fields is the largest of all sapphire mining areas in Australia with an area of around 900 sq. km. Immediately after picking up the enormous black crystal the boy lost no time in running back home to show his accidental find, to his father Mr. Harry Spencer, who was one of the pioneering miners of the central Queensland gemfields. Mr. Harry Spencer was not impressed, and after examining the enormous black crystal just threw it aside, saying it was just a large black crystal. Perhaps it was not known at that time that sapphires could also exist as black gemstones. The enormous black crystal was then fortunately used as a door stop, in the Harry Spencer household for around a decade, without being thrown away as something worthless.

Realization of the true value of the stone

After about a decade Mr Harry Spencer came to know that sapphires do indeed exist sometimes as black gemstones, and may be worth quite a fortune depending on its quality. He subjected the humble black stone, that had served him well for almost a decade as a door stop, to thorough examination and realized that it may be worth a fortune. He weighed the stone and found that it weighed an enormous 1,156 carats. Mr Spencer was quite sure of the quality of the stone, but was not experienced enough to detect that the stone could eventually be transformed into a star sapphire. The humble door stop that was treated with scant respect for almost a decade, was suddenly elevated to a higher status, and began receiving royal treatment from the poor miner. The gemstone was washed well and wiped and kept in a safe place, until a prospective buyer could be found.

The sale of the rough black stone to Harry Kazanjian

The word got around quickly that an enormous gem-quality rough black sapphire was available for sale, and in 1947, the Armenian-born jeweler Harry Kazanjian traveled all the way from his adopted home town of Los Angeles, in California, to have a look at the sapphire with a view of purchasing it. Harry Kazanjian examined the enormous black stone and was impressed, and immediately started negotiations with Harry Spencer for the purchase of the gemstone. Finally Harry Kazanjian agreed to pay $ 18,000 for the gemstone, which Harry Spencer accepted. The agreed amount was duly paid, and the black stone which had remained in the Spencer household for almost 10 years, changed hands.

Cutting of the rough black stone into a black star sapphire

With the money realized Harry Spencer was able to construct a new house for his family. Harry Kazanjian carried the rough gemstone to Los Angeles, where he studied the sapphire for at least two months. Through his long years of experience in examining rough stones Harry Kazangian was convinced of the hidden asterism in the rough stone, and accordingly cut the stone as an oval cabochon, sacrificing 423 carats of the rough stone. The finished black sapphire that weighed 733 carats, revealed a brilliant six-pointed star when exposed to natural or artificial light. Like all other star sapphires the star was more pronounced when the source of light, such as direct rays of sunlight or light originating from a pen torch, was directed straight at the dome-shaped face of the stone. Cutting a star sapphire is an expert job, and needs experience and special skills. A wrong judgment or an error may result in a failed star, or a star with some rays missing or star displaced to a side. The estimated value of the expertly cut black star sapphire was $ 1 million in the year 1949.

Display of the Black Star Sapphire of Queensland at the Royal Ontario Museum

In the year 2007, the new owner of the Black Star Sapphire of Queensland, who purchased it in 2002 from its anonymous owner, loaned the rare gemstone to the Royal Ontario Museum of Canada, for an exhibition organized in connection with the Architectural Opening and Building Dedication of the Michael Lee-Chin Crystal on June 2nd 2007, an ultra modern building designed by the architect Daniel Libeskind. This is the second time the unique gemstone had gone on display after its first display in 1969, at the Natural History Museum of the Smithsonian Institution, at Washington DC. The Black Star of Queensland was exhibited with the surrounding band of 35 smaller white diamonds, and was the centerpiece of a general exhibit, that explained all aspects of the gemstone known as sapphires, such as their chemistry and structure, how sapphires were formed in nature, the distribution of sapphires in the world, the mining of sapphires, and the importance attached to sapphires in different cultures.