The Most Expensive Gemstones in the World

What makes a gemstone worth millions of dollars? The answer lies in an extraordinary convergence of colour, clarity, size, rarity, and provenance. While most people think of diamonds as the most expensive gems, the reality is that per-carat prices for the finest coloured gemstones, particularly rubies, can far exceed those of white diamonds. This guide explores the gemstones that command the highest prices, the factors that drive their values, and some of the most remarkable auction records in history.

Most Expensive Gemstones by Type

What Drives Gemstone Prices?

Colour

Colour is the single most important value factor for coloured gemstones. The difference between a "good" and "exceptional" colour can mean a ten-fold or even hundred-fold difference in price per carat. The most prized colours, such as pigeon blood red in rubies, cornflower blue in sapphires, and vivid green in emeralds, represent a narrow range of hue, saturation, and tone that only a tiny fraction of rough material achieves.

Rarity

Gemstones from depleted or limited sources command significant premiums. Kashmir sapphires, with their mines largely inactive since the 1930s, are valued as much for their scarcity as their beauty. Similarly, Paraiba tourmalines from the original Brazilian deposit, Brazilian alexandrites, and Russian demantoid garnets are prized because their sources have either been exhausted or produce only tiny quantities.

Treatment Status

Untreated gemstones of fine quality often carry substantial premiums over treated stones. In top-tier material, the gap can be very large, but it varies considerably by stone type, quality level, laboratory opinion, and market conditions. For more on treatments, see our natural vs synthetic gemstones guide.

Origin

Certain origins carry historical prestige and premium pricing. Kashmir for sapphires, Burma for rubies, and Colombia for emeralds are the most notable examples. Origin alone can materially affect value, though the premium varies widely and only matters when the stone itself is already fine enough to justify origin-sensitive pricing.

Size

For all gemstones, price per carat increases exponentially with size. A 5-carat ruby of given quality may cost ten times more per carat than a 1-carat stone of the same quality. Truly large stones of exceptional quality are vanishingly rare and command record prices.

Record-Breaking Gemstone Sales

The Sunrise Ruby

The Sunrise Ruby, a 25.59-carat Burmese pigeon blood ruby, sold at Sotheby's Geneva in May 2015 for $30.42 million (approximately $1.19 million per carat). It holds the record as the most expensive ruby and the most expensive coloured gemstone other than diamond ever sold at auction.

The Rockefeller Emerald

This 18.04-carat rectangular step-cut Colombian emerald, once owned by John D. Rockefeller Jr., sold at Christie's New York in June 2017 for $5.51 million ($305,516 per carat), setting a per-carat record for emeralds at auction.

The Blue Moon of Josephine

The Blue Moon of Josephine, a 12.03-carat fancy vivid blue diamond, sold at Sotheby's Geneva in November 2015 for $48.47 million ($4.03 million per carat), setting a world record price per carat for any gemstone at auction.

The Kashmir Sapphire Record

Fine Kashmir sapphires regularly set records at auction. In 2015, a 35.09-carat Kashmir sapphire sold at Christie's for $7.35 million. Auction performance for top Kashmir stones has been exceptionally strong, though the market is thin and highly selective.

Coloured Diamonds: A Special Category

While this guide focuses on coloured gemstones, it is worth noting that fancy coloured diamonds occupy a unique position at the very top of the gemstone value pyramid. Red diamonds are considered the rarest of all gemstones, with only a handful of true reds known to exist. Blue, pink, and green diamonds also command extraordinary prices, driven by their extreme rarity and the strong global demand for diamonds of any colour.

Investing in Expensive Gemstones

• Focus on quality over size – A smaller stone of exceptional quality and provenance is often more defensible than a larger stone of average quality.
• Prioritise untreated material – Untreated stones tend to be more desirable in the top end of the market, but premiums still depend on rarity, quality, and documentation.
• Obtain comprehensive documentation – For investment-grade stones, obtain reports from multiple respected laboratories. A stone documented by both GIA and Gubelin, for example, provides maximum buyer confidence.
• Consider provenance – Stones with notable provenance, such as celebrity ownership, historical significance, or inclusion in famous collections, carry additional value.
• Buy the best you can afford – In the gemstone market, rarity and quality tend to matter more than quantity, but appreciation is never guaranteed.
• Be patient – Gemstones are long-term, illiquid holdings. Anyone entering this market should assume slow exits and uneven pricing.

Where the Most Expensive Gemstones Are Sold

The highest-value gemstones typically change hands through major auction houses (Christie's, Sotheby's, Bonhams), specialist dealers with established reputations, and private sales facilitated by industry intermediaries. For buyers entering this market, establishing relationships with trusted dealers and auction specialists is essential. Our buying guides offer practical purchasing advice.

Affordable Alternatives

Not everyone can invest in a six-figure gemstone, but you can still enjoy beautiful stones that offer excellent value:

• Tanzanite offers sapphire-like colour at a fraction of the price
• Tsavorite garnet provides vivid green rivalling emerald with better clarity
• Spinel offers rich reds and blues similar to ruby and sapphire at lower prices
• Aquamarine delivers serene blue beauty at very accessible prices
• Amethyst provides rich purple colour at remarkable value

Conclusion

The world's most expensive gemstones represent the pinnacle of natural beauty and rarity. From record-breaking rubies to one-of-a-kind coloured diamonds, these extraordinary stones are the product of millions of years of geological processes and, in many cases, will never be replicated. Whether you aspire to own one of these treasures or simply appreciate their magnificence from afar, understanding what drives their extraordinary value deepens your appreciation of the entire gemstone world.