Sapphire is one of the world’s noblest, most fascinating and best-known gemstones. In fact, it owes its popularity to its strength, density, hardness and multiple hues. In ancient civilizations, only sovereigns or high dignitaries could adorn themselves with this stone, as it evokes prestige and luxury. Today, in any jewelry store in France, you can buy rings, earrings or pendants designed with sapphire. The question is, where does this stone come from? Planetys helps you find out about the world’s main sapphire deposits.
How is sapphire formed?
Like ruby, sapphire is a gemstone belonging to the corundum family. It is composed largely of aluminum oxide. According to many scientists interviewed, this gemstone is formed in the bowels of the Earth at a depth of around 50 km. It emanates precisely from a parent rock rich in silicon and aluminum AL2SIO5. The gem really begins to take shape beneath the earth’s surface when the pressure reaches 20,000 bar and the temperature approaches 1,100°C. Under the action of magma, the raw sapphire formed in the lithosphere is expelled into the earth’s crust.
Generally speaking, sapphire crystallizes in hard rocks and is rhombohedral in shape. Iron, titanium, chromium, vanadium, magnesium… Many transitional chemical elements can be found in the composition of sapphire, giving it a specific color. For example, if sapphire contains only iron and titanium in its structure, it takes on a blue color. If it contains only iron, it takes on a yellow hue. When it is free of impurities, its hue is white. Whether light or dark, sapphire, unlike cabochon, contains few inclusions.
Sapphire deposits around the world
Where are sapphires found?
According to geologists, the most important deposits of these precious stones are located in Southeast Asia and Africa.
Deposits in Myanmar
Myanmar (formerly Burma) is known not only for its top-quality rubies. In the north of the country, precisely in the Mogok area, there are major sapphire deposits. The gems extracted from these mines have an intense blue color and are among the most prized by jewelers. To extract Burmese sapphires, miners use spades and baskets. They generally dig a shaft 5 to 30 meters deep. The absence of modern tools makes extraction a laborious task, especially when climatic conditions are unfavorable.
Sri Lanka’s deposits
The world’s best sapphire mine is located in Sri Lanka (Ceylon), in the town of Ratnapura. It is located 80 kilometers southeast of Colombo. This mine contains gems in a variety of colors (pale blue, yellow, orange, green…). The deposit has been mined in this country since antiquity and is packed with important gems such as rubies, topaz and zircons. As for sapphires, they are thermally reprocessed before being sold on the Bangkok market.
Deposits in Thailand
Thailand is the world’s most important trading center for sapphires and rubies. In addition to its reputation as a gemstone trading hub, it is also a major exporter of sapphires. It has two major deposits.
The first is located southeast of Bangkok, in the town of Chantaburi. The second is a few meters from the Cambodian border, in the northwest of the country, at Kanchanaburi. Unlike the mines in Myanmar, those in Thailand are operated with state-of-the-art machinery. Most of the crystals extracted are a deep, dark blue.
Cambodian deposits
Still known as Siam, Cambodian sapphires are not as popular as those from the other countries mentioned above. They come from the Pailin deposit in Battambang province. These stones have an attractive, luminous color. Since they are found in low proportions, they are sold at high carat prices.
Australian deposits
Australia has two sapphire mining areas. The first is northwest of Brisbane in Queensland. The second is located in a small town north of Sydney, around Inverell. The gems from these two deposits are not much sought-after by jewellers, but are still of excellent quality.
Deposits in Kashmir
The main sapphire mining areas in Kashmir were once located in the Zaskar region. These mines provided some of the finest gems in the world. Today, corundum is hard to find in Kashmir, as the main deposits have become barren. The state authorities have therefore decided to close them down.
Brazilian deposits
Brazil is known for its sapphire deposits in certain regions of the country, such as Minas Gerais, Bahia, Ceará (Quixada) and Rio Grande do Sul. Brazilian sapphires come in a variety of colors, including blue, green, yellow, pink and violet. Blue is the most common color, but it is also possible to find Brazilian sapphires in intense, vivid hues. Brazilian sapphires can vary in saturation, from pale, subtle hues to deep, rich colors.
Mozambique deposits
Famous for its rubies, Mozambique also exports magnificent pink sapphires. The purity of these gems is comparable to that of sapphires from Madagascar or Ceylon. Mozambique sapphires have been on the market for 10 years, but production remains low.
Nigerian deposits
Nigeria is one of the world’s most gem-rich countries. Sapphire, the country’s most important corundum, is produced on the Mambila plateau. It is a deep blue of unparalleled purity. Due to their characteristics, most sapphires from this country are sold at the same price as those from Madagascar or Ceylon. With Nigeria’s deposits only recently exploited (2014), sapphires from this country still have a bright future, as do those from Kenya.
Vietnamese deposits
One of the world’s leading producers of ruby and spinel, Vietnam is also known worldwide for its sapphires of various qualities and colors. Among the gems it markets are orange and dark blue sapphires. Located in Quy Nhon province, 200 km southwest of Hanoi, Vietnam’s sapphire deposits are not very productive. This explains the scarcity of this type of sapphire on the market.
Tanzania’s deposits
Tanzania’s sapphire mines were discovered in the Umba Valley in the 1950s. This region in the north-east of the country borders Tsavo Park, an area rich in tsavorite garnets. In this valley, there are blue, orange, pink, violet and even Padparadja sapphires. According to numerous investigations, there are other deposits in the Uluguru mountains that contain sapphire of excellent quality.
Madagascar’s deposits
Madagascar is one of the world’s leading sapphire producers and home to a number of important deposits. Here are some of the main sapphire deposits in Madagascar:
- Ilakaka: Located in the Ihorombe region, the Ilakaka deposit is one of Madagascar’s most famous. It was discovered in the 1990s and is renowned for its blue and multicolored sapphires.
- Andranondambo: This deposit is located in the Fianarantsoa region of southern Madagascar. It is renowned for its blue and green sapphires.
- Ambatondrazaka: In the Alaotra-Mangoro region, the Ambatondrazaka deposit is known for its blue and yellow sapphires. It was discovered in the 1990s and is still being mined today.
- Vatomandry: This deposit is located in the Atsinanana region, on Madagascar’s east coast. It is known for its blue and green sapphires, as well as for its large gemstones.
- Andranondambo: This deposit is located in the Androy region of southern Madagascar. It is renowned for its blue, green and pink sapphires. These sapphire deposits in Madagascar have contributed to the island’s reputation as a major source of high-quality sapphires.
Deposits in the USA
There are several sapphire deposits in the United States. Here are just a few examples:
- Montana: The state of Montana is famous for its sapphire deposits. The Rock Creek area of Granite County is known for its high-quality sapphires.
- The town of Philipsburg is home to several sapphire mines that allow visitors to search for and collect their own gems.
- North Carolina: In the mountains of western North Carolina, there are sapphire deposits near the town of Franklin. The region is renowned for its brightly colored sapphires, ranging from deep blue to violet.
- Idaho: Idaho also has sapphire deposits. The area around the town of Sapphire in Lemhi County is particularly well known for its gem-quality sapphires. Commercial mines allow visitors to search for sapphires and buy them.
- California: California also has a number of sapphire deposits. The Riverside and San Diego regions are known for their sapphires, particularly in the Pala and Ramona areas.
Where can I find sapphires in France?
In France, sapphires are found in alluvial form in numerous rivers in the Auvergne, Puy-de-Dôme and Haute-Loireregions… To extract them, you can use a beater like a gold digger. Most of these gems are not very valuable, however, and are considered collector’s items. Jewellers find them of no interest.
