The cornflower blue sapphire, with its luminous pure blue gleam, has always been one of the most valuable and coveted gemstones. And since the 1980s, when Princess Diana
chose an iconic 12 carat oval blue Ceylon sapphire
ring as her engagement ring, the sapphire has been a popular classic choice for engagement rings.
The origin of cornflower blue sapphires
The cornflower is one of the few flowers that is purely blue, rather than violet or purple, so a cornflower blue sapphire is a gemstone with a color similar to the intense blue color of a cornflower. Sapphires generally have undertones of green or purple, while a cornflower blue sapphire is said to be closer to “true” blue, along with excellent tone and saturation to highlight the purity of the color.
While the term “cornflower blue” is more descriptive than scientifically precise, it is extremely rare to find a sapphire of pure blue, so these are particularly prized.
In November 2013, a 114.74 carat untreated cornflower blue Burmese sapphire sold for $7,223,285 at Sotheby’s Geneva. Not only is this an extraordinary size for a high quality natural sapphire, the cornflower blue color makes it particularly valuable.
Other color variations of sapphire include yellow
(or golden sapphire, if the color is particularly vibrant), pink sapphire
, green sapphire, purple sapphire, orange sapphire, black sapphire and white sapphire.
Defining the color of a sapphire
For a sapphire to be called “blue”, the primary color of blue must account for at least 85% of the gemstone’s color. Common secondary colors are green or purple. The most prized blue sapphires are velvety blue to violet blue in medium to medium dark tones, with vivid color saturation. Sapphires are dichroic stones, which means their color will vary when viewed from different angles, so a skilled gem cutter will make the most of the dominant color when choosing the cut for the stone. The Yogo sapphires, sourced from Yogo Gulch in Montana, USA are typically cornflower blue with high clarity and brilliance. Their color originates from trace amounts of iron and titanium.
A sapphire’s inclusions
Most sapphires also contain minor inclusions, known as rutile needles or “silk” which decrease the transparency of the stone. As these inclusions are so common, a sapphire without inclusions would be suspected of being fake or treated. In rare cases, light can reflect of the inclusions to create a star effect or “asterism” which increases the value of the gemstone.
At Israel Diamonds, we stock a wide range of loose sapphires, including spectacular Ceylon sapphires. Contact us today if you want to create your own unique cornflower blue sapphire engagement ring or any other spectacular piece of jewelry.