Blue sapphires are one of the most celebrated of all gemstones. They are sought after for their vibrant color and their value. In recent years, blue sapphires have set record prices at auction. And throughout history, sapphires have been coveted by royalty around the globe as a symbol of wealth and sovereignty. Going back to ancient times, sapphires were said to have mystical powers that included calming the mind, attracting wealth, repelling envy and creating harmony between lovers. Sapphire is the birthstone for September and is connected to both the fifth and 45th wedding anniversaries.

Some famous sapphires are the Star of India, a 563.35-carat blue sapphire that resides in the American Museum of Natural History in New York City; the 423-carat Logan Sapphire, which is on display in the Smithsonian Institution in Washington, D.C., and the Stuart Sapphire, which is part of the British Crown Jewels and can be found in the Tower of London.

Sapphire is made up of aluminum oxide and gets its blue color from trace elements of titanium and iron. On the Mohs Scale, which measures a gemstone’s hardness with a rating of one to ten, a sapphire is a number nine — the only stone harder than sapphire on the Mohs Scale is diamond at ten — making it very durable for everyday wear and a popular choice for engagement rings. One of the most famous blue sapphire engagement rings was the one given to Princess Diana by Prince Charles. That ring is now worn by Kate Middleton, Duchess of Cambridge, who was gifted the ring by her husband Prince William upon their engagement.

Much is made of where a gemstone comes from, known as its origin. And sapphire origin is a topic that comes up often and can greatly affect the value of the stone. For the purposes of this post, we will take a look at blue sapphires from Kashmir, Burma and Ceylon.

“At the highest level, the origin has a huge impact on price. We always advise consumers to buy gems, not paper,” comments Richard Hughes, gemologist and author of the book Ruby & Sapphire: A Collector’s Guide. “Stones from different sources tend to look slightly different, but such differences are subtle. Most origin determinations are based on inclusions in the stones,” he says.

In general, a high-quality blue sapphire will have a blue to violet-blue shade that is a well-saturated, vibrant color with a medium tone. If the sapphire is too dark, it will diminish the brightness of the stone. The better the clarity, the more valuable the stone. Sapphires are often heated to enhance their color, which decreases the value of the stones. The most valuable stones are the ones in which the color occurs naturally and do not need treatment to bring out their color.

Origin is determined by gemological laboratories using various tools that analyze inclusions, growth structure and chemical composition. In some cases, there are certain characteristics that are unique to one area, while in other cases, there will be overlapping traits from one source to the next, making origin determinations a combination of art and science.

Here’s a bit of background on where sapphires come from.

CEYLON

Ceylon, now known as Sri Lanka, is an island off the coast of India. The island is so abundant in gemstones of all sorts that at one time it was known as “Gem Island” or “Island of Jewels.” According to legend, King Solomon wooed the Queen of Sheba with jewels from Ceylon. The island is also known for producing rubber, rice and tea.

Sapphires from Ceylon are thought to be the first ever discovered, about 2,000 years ago. Today, Ceylon is one of the top-producing countries of untreated sapphires. The color is generally clustered toward the top of the stone. This gives the gem an even distribution of color as well as uniform color and brightness.

KASHMIR

Kashmir is located in the northwest region of India. It had sapphire mines that produced an abundance of gems between 1881 and 1887 before it ran out of the blue stones. Kashmir sapphires are widely considered to be the best of the best of sapphires and they sell for a premium price, in part because of their rarity. Now that virtually no gems come out of the mine, the supply is limited to those produced during its seven-year run. While there have been explorations for blue sapphire in the Kashmir area since that time, no significant new finds have come about. Kashmir sapphires have threadlike, intersecting rutile needles in the stone known as “silk” that give the gems a lush, velvety look due to the way the light scatters on the rutiles.

BURMA

Sapphires from Burma — a country in Southeast Asia known for its rubies —  tend to be a bit darker, sometimes a violet blue color. The stones are found mostly in the Mogok and Mong Hsu areas of Burma alongside ruby, as both gems are the same species of rock — corundum. The difference between a sapphire and ruby is that ruby is red; any other color of corundum that is not red or blue is also sapphire and is referred to as fancy color sapphire.

Burma sapphires tend to be a bit more transparent than Kashmir sapphires, with very few inclusions. Sapphires from Burma have very little to no color zoning, a trait that can be found in sapphires from other areas.

There are many factors to consider when purchasing a gemstone or piece of jewelry with a significant blue sapphire, but Hughes sums it up well with the following advice: “Choose a gem that attracts you personally. I also suggest that you buy untreated gems.”