I love gemstones but I really love expensive gemstones, not only because they are often the finest examples ever found but also because they are incredibly rare (which is why they are so expensive) but what are the most expensive gemstones in the world?
But, before I get to the stones I need to explain how I have figured out this list as there was more than one way I could do it but I opted for the highest price per carat that has been achieved, as price per carat is the way that most gemstones are valued rather than price per piece, which I used for my other most expensive lists.
I hope you find them as amazing as I did!
10: Yellow Diamonds – $163,000 Per Carat
Yellow diamonds are some of the cheaper fancy coloured diamonds, even though $163,000 per carat is not exactly cheap!
This was the price per carat achieved by the Graff Yellow Diamond in May 2014, when it sold for $163 Million, which is also a world record price for a fancy yellow diamond.
The reason why yellow diamonds are cheaper than some other fancy colours is that they are:
- Rarity – It is estimated for every 16,500 carats that are mined, one carat will be a fancy yellow, which means yellow diamonds are rare but not as rare as others and it is also estimated that around 60% of fancy coloured diamond are yellow
- Size – Yellow diamonds can be found in very large rough crystals, meaning that they can be cut into large faceted stone. For example the Graff Yellow weights 100.09 carats and the Red Cross Yellow Diamond (second most expensive yellow) weights 205.07 carats
This combination means that yellow diamonds are worth significantly less per carat than some of the other fancy colours as you will see.
9: Blue Sapphire – $243,000 per carat
While not the rarest colour of Sapphire, Blue is by far the most valuable as it is the colour most widely attached and also desired.
But for reasons similar to yellow diamonds, Blue Sapphires have lower prices per carat than the other members of the Big 4 gemstones.
Even though the record price of $243,000 per carat achieved by the Jewel of Kashmir Sapphire in October 2015 isn’t exactly small!
There are a few Sapphires that have achieved a $200,000 per carat price and they all share a similar feature in that they are all Kashmir Sapphires, which is the most desirable source of blue sapphire and as these deposits have been mined out for more than a century, prices are likely to rise for these stones.
But it is not a Sapphire from Kashmir that holds the title of world’s most expensive Sapphire, that is held by the Blue Belle of Asia, which sold for $17.5 million and came from Ceylon (now Sri Lanka) but weighing 392.52 carats meant that it only achieved a price per carat of around $44,000.
8: White Diamonds – $282,000 per carat
Technically, White Diamonds aren’t white, they are colourless (you can get white Diamonds but they are very rare) but it is the trade name that is used for them.
And it is the Type IIa White Diamonds that attract the highest price per carat as these types of diamond have little to no impurities in the form of nitrogen or boron, which cause yellow and blue respectively, meaning that Type IIa diamonds are chemically the most pure.
But not all Type IIa diamonds are colourless, some browns and pinks can also be Type IIa.
But Type IIa diamonds are very rare with an estimated 1-2% of all mined diamonds falling into this category but there is a unique feature with Type IIa White Diamonds in the the crystals can be very large and that is why all of the large faceted White Diamonds are Type IIa.
In terms of price, they are on the lower end of scale for Diamonds for reasons similar to the the yellow diamonds but these large colourless Diamonds often achieve prices per carat in excess of $200,000, with the Archduke Joseph Diamond holding the record at $282,000 a carat.
But this is not the most expensive White Diamond, that title is held by the Spirit de Grisogono, which is a 163.41 carat diamond that sold for $33.7 million in November 2017, with a price per carat of just over $206,000.
7: Emerald – $305,000 per carat
The most desirable and expensive member of the Beryl family of gemstones is Emerald, with the finest examples coming from the famed Colombian Emerald mines.
Which is where the Rockefeller Emerald came from, which achieved the $305,000 per carat price when it was sold in June 2017.
And what makes this such an extraordinary Emerald is that is hasn’t been treated, which is extremely unusual for a stone of this size and clarity, the provenance of being owned by one of the wealthiest and most famous families in American history probably also helped the price.
But the Rockefeller Emerald is not the most expensive Emerald, that title is held by a 23.46 carat, Colombian Emerald that was owned by Elizabeth Taylor and sold for $6.5 Million at a special sale in December 2011.
6: Ruby – $1.2 Million per carat
That is quite a jump in price per carat!
But Rubies are the second most expensive gemstone behind Diamond and there a few spectacular examples that have broken the $1 million per carat range.
Including the record setting Crimson Flame Ruby, which sold for $1.2 Million per carat in December 2015 but the sale price of $18.2 Million for the 15.04 carat stone wasn’t enough to make it the most expensive.
No, that title is held by the 25.59 carat Sunrise Ruby, which sold for $30.3 Million in May 2015 and is still the most expensive Ruby by some margin as the Crimson Flame sits in second.
Both of these Rubies share similar characteristics as they both come from the famed Ruby mines in the Mogok region of Burma (now Myanmar), neither has been subjected to any kind of treatment and they both posses the highly desirable although unpleasantly named ‘pigeon blood’ colour.
5: Orange Diamonds – $2.40 Million per carat
Pure Orange Diamonds are one of the rarest and in some cases underappreciated colours that can be found in Diamond (Blues and Pinks are more much more popular).
And this is evidenced by the small number of pure Orange Diamonds that have ever been offered at auction but they have certainly sold for good money.
But one Diamond, simply known as The Orange is arguably the finest orange diamond in history.
This is because when the 14.82 carat diamond was graded by the GIA, they included a letter that stated ‘According to the records of the GIA Laboratory (this diamond) is the largest Fancy Vivid Orange, Natural Colour, diamond graded as of the date of the report issued.’
And the $35.5 million sale price most definitely reflected this uniqueness and that works out at just over $2.4 million per carat. Now this stone is pretty much a one off but other fancy orange diamonds have sold for $707,000 and $609,000 per carat, meaning that without The Orange, orange diamonds would only swap places with Rubies on this list.
4: Red Diamonds – $2.42 Million per carat
Red Diamonds just beat Orange in terms of price per carat at $2.42 Million, which was achieved by The Moussaieff Red Diamond in November 2014, the $5 Million sale price is also the highest price ever achieved by a Red Diamond.
Pure red is the rarest colour in Diamond and like orange, they rarely come up for auction, so when they do, they fetch a good price, with other examples selling for $1.8 million and $1.6 million per carat.
But Red Diamonds are not only very rare but they are also quite small, especially when compared to other Diamonds and the largest cut Red Diamond is only 5.11 carats (I know I just said only for a 5 carat diamond), which is owned by Moussaieff and would most definitely break all known records if it was ever sold.
But most Red Diamonds weigh less than 2 carats, with very few examples weighing more than this, such as the two mentioned and the Argyle Everglow, which weighs 2.11 carats.
3: Green Diamonds – $3.3 Million per carat
Coming in second are Green Diamonds and I seem to be saying this a lot but these are very rare and only a few true greens have ever been offered at auction.
And the 5.03 carat Aurora Green broke two records when it sold in May 2016, not only was it the highest price per carat at $3.3 Million but the $16.7 Million sale price was also a world record price.
This smashed the previous record set by a 2.54 carat Fancy Green Diamond in November 2009, which sold for $3.08 Million and $1.2 Million per carat.
The green colour is most often caused by being exposed to radiation in the earths crust for thousands or millions of years but with many green diamonds, the colour often only penetrates to a depth of around 0.02mm and may often be removed when the stone is cut.
On very rare occasions, the colour penetrates completely and gives an even saturation of colour across the body of the stone and results in a pure green colour, with the most famous example of this being the 41 carat Dresden Green Diamond.
2: Blue Diamonds – $4 Million per carat
The title of most expensive gemstone was held by blue diamonds for nearly 7 years and it was achieved by the 12.03 carat Blue Moon of Josephine, which achieved $4 million per carat when it sold in November 2015.
On many lists, The Oppenheimer Blue Diamond is quoted as being the most expensive per carat at $3.9 million, which as is just shy of the Blue Moons $4 million per carat but the 14.62 carat Oppenheimer Blue does hold the record for the most expensive Blue Diamond at $57.8 million when it sold in May 2016.
But unlike many of the other stones on this list where it has been one or two fine examples of these stones that have achieved incredible prices per carat, Blue Diamonds have done this consistently, with 5 of the top 10 achieving more than $3 million per carat.
1: Pink Diamonds – $5.1 Million per carat
In 2022, Pink Diamonds took the crown of the most expensive gemstone when the 11.15 carat The Williamson Pink Star diamond achieved over $5.1 million per carat.
This smashed the $4 million achieved by the Blue Moon of Josephine in 2015 and has set an incredibly high benchmark in terms of price per carat.
But it is not the most expensive Pink Diamond, that title is held by the Pink Star Diamond, which sold for $71.1 Million in April 2017 but the 59.60 carat stone only cost $1.1 Million per carat, which I am sure you will agree is very reasonable.
The prices for Pink Diamonds are expected to rise in the future due to the closure of the Argyle Mine in Western Australia in 2020, which was the world’s leading source of these gorgeous diamonds.
Conclusion
There are some impressive gemstones on this list aren’t there?
And obviously there are many other valuable gemstones out there which can sell for many thousands of dollars a carat but for this list, I just decided to look at the top 10 as it is a nice round number.
There are also examples such as the Marie Antoinette Natural Pearl, which sold for $36.1 million and the Barbara Hutton-Mdivani Jade Necklace, which sold for $27.2 million but it is difficult to calculate the price per carat of these stones, which is why they didn’t make the list.
I'm Paul Haywood FGA DGA, a fully qualified Gemmologist and Diamond Grader from the Gemmological Association of Great Britain and a lover of all things jewellery.