Celestial Sapphires : Digging Deep into Sapphire Mining

Rachel Carr
Rachel Carr - Editor
Natural sapphire gemstones

As one of the many ores recovered by mining, the sapphire gemstone is traditionally connected to the sky, but its roots began firmly in the ground in Kashmir, India.


Sapphires have been mined for centuries, but occasionally new deposits are discovered that capture the attention of the mining world and gemstone market. Traditionally, mines in Kashmir, Myanmar, and Sri Lanka produced the world’s high-quality sapphires. Just two of these three locations remain, with the last sapphire being mined in Kashmir in 1927.

The gems are now mined in myriad places across the globe. Fascinatingly enough, they are not all blue, and two of the rarest colours include padparadscha and cornflower blue. Both were found high in the Zanskar Range of the Himalayas, although, some of the most interesting colours hail from mines in Africa.


Along with its notoriety for diamond mines, Africa has emerged in prominence for its wealth of sapphire supplies. Rwanda, Malawi, Laos, Cambodia, Cameroon, Kenya, Ethiopia, and Mozambique all harbour the precious gemstones; however, Nigeria is the most important producer of sapphires in West Africa, where they have been mined in the central part of the country for around 30 years. 

In 2014, Nigerian sapphires caused waves in the industry after the discovery of a substantial number of high-quality sapphires, which were recognised for their attractive size, high clarity, good colour, and strong crystal habit. Southern Madagascar joined the sapphire mining map in the late 1990s when a large deposit was discovered in the small town of Ilakaka. The size of this deposit stood out as a rare discovery for the present day.  

Elsewhere in Africa, Tanzania acquires many of its rarer gems from the Umba River Valley. This gravel area has yielded sapphires of all shades including the highly valued padparadscha colour. Although, Songea is the most productive sapphire mining region, recent discoveries near Kibuko have produced pink sapphires of up to 100 carats. 

Across the rest of the world, Australia, Thailand, Myanmar, China, Vietnam, Afghanistan, and Columbia are also part of the mining map. 


Montana is the only source of sapphire mining in the US, and its nickname ‘The Treasure State’ is for good reason due to its abundant natural and mineral resources. Initially, the sapphires were a by-product of the gold rush of the 1860s, but more recently, the deposits throughout Montana have surrendered high-clarity sapphires. These are extremely unique since these particular gemstones have no cavities. 

The state’s most precious sapphires are found in the Yogo Gulch area, located in the Little Belt Mountains of Montana, which are igneous rather than metamorphic, like many other sapphires. The unique gems are considered some of the finest in the world. Visual properties include an even colour of cornflower blue, as a result of trace amounts of iron, but they are also found in shades of violet and purple. While other distinguishable features lie in the trace element concentrations with elevated levels of magnesium and titanium content. 


In 1865, Montana man Ed R Collins discovered that the stones had value when he sent samples to Tiffany & Co, the jewellery company declared that the gems were “sapphires of unusual quality,” and a small sapphire rush began. Famed for their clarity and brilliance, many of the Montana sapphires are used for engagement rings. In fact, the gems have enjoyed a renaissance from the Princess Diana effect when she received a stunning 12-carat sapphire engagement ring, worth almost $400,000 today. It is now known that the oval sapphire is of Sri Lankan origin. 

Other famous sapphires include The Star of Adam, worth a staggering $300 million, and the Stuart Sapphire, which is set into the Imperial State Crown of England. However, the world’s biggest star sapphire cluster was uncovered in Ratnapura, Sri Lanka, weighing in at 2.5 million carats and known as the Serendipity Sapphire. 


Sri Lanka has been mining sapphires for almost 2,000 years with little change to its mining operations or construction. Mined in primarily alluvial deposits, using the tunnel mining method, the operations are small scale, and the gems are ethically sourced. Larger scale projects are restricted to minimise the environmental impact and ensure the longevity of the supply, and open pit operations are permitted providing that the area is revegetated. 

The Sri Lankan government does not allow environmentally or economically unstable mining activities. Sapphires are generally mined from less troubled communities across the mining map; therefore, they are more ethical and eco-friendlier than other gemstones, with traceable beginnings. Coupled with their vivid colours, these details make them one of the most sought-after gems around the world. 



  • Sapphires are ranked nine out of 10 on the Mohs Scale for durability, third behind diamonds and moissanite respectively.
  • Besides jewellery, sapphires are used to create Swiss timepieces, Apple watches, scientific instruments, and high-durability windows. 
  • Yellow sapphires are caused by the presence of iron without titanium. 
  • The largest cut and polished sapphire is the Millennium Sapphire, with a weight of 61,500 carats.


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By Rachel Carr Editor
Rachel Carr is an in-house writer for Mining Outlook Magazine, where she is responsible for interviewing corporate executives and crafting original features for the magazine, corporate brochures, and the digital platform.