Tangible assets that are uncorrelated with traditional financial markets and easier to transport than gold or real estate, precious stones are a little-known safe haven. Rare and prized by jewelers and aesthetes around the world, the four essential precious stones (diamond, sapphire, ruby, and emerald) are facing more competition than ever from semi-precious stones such as tanzanite and spinel.
There are said to be only four precious stones of value on the face of the earth: diamonds, sapphires, rubies, and emeralds. These stones, with their unparalleled brilliance, are seeing their prices rise by 50 to 150% for the most common ones between 2015 and 2025, and even more for the rarest ones.
However, given the current or future depletion of the main gemstone mining sites, there is a shift towards semi-precious stones.
Thus, inflationary pressures and economic and geopolitical uncertainty are prompting jewelers and individuals to opt for these colored stones, which, like precious stones, represent an investment in heritage. As such, they should be kept for 5 to 10 years, or even longer, if you wish to pass them on to your children or loved ones.
Programmed disappearance
In the glittering world of jewelry, the four precious stones, long favored almost exclusively by the great Houses, are proving increasingly difficult to obtain. So much so that their auction prices range from hundreds of thousands of euros to several million for so-called exceptional stones.
These stones can be found and mounted on jewelry by experts with exceptional know-how, such as the gemologist and jeweler Bonnot Paris.
Although the diamond remains the precious stone par excellence, its price has fallen in recent years, particularly in the face of the development of laboratory-grown diamonds. It currently costs between $15,000 and $30,000 per carat. The rarest is now the blue diamond. At $4 million per carat, it is now the most expensive precious stone in the world.
Renowned as the most desirable ruby in the world, the Burmese ruby is facing the depletion of its mines in Mogok, the main extraction site, well known to gemologists and cited in their bedside book, The Valley of Rubies, written in the 1930s by Joseph Kessel. The area is also known for its famous pigeon blood rubies, reputed to be the most beautiful in the world.
Among the other difficulties facing rubies is the embargo imposed on these stones due to the persecution of the Rohingya, a Muslim ethnic group. These difficulties are prompting professionals to source their supplies from close neighbors. As a result, Thai rubies are now preferred by the luxury industry. When this is not the case, antique Burmese rubies from the second-hand market are the obvious choice.
Nevertheless, the situation is a boon for collectors, as a beautiful ruby is now valued as highly as a beautiful diamond. This scarlet gemstone has experienced a real boom since the 2000s. In 2015, the 25.59-carat Sunrise Ruby from Burma sold for $30.4 million at Sotheby’s.
However, these exceptional auction sales do not reflect the actual price for the general public. A ruby on the retail market tends to cost between $118 and $17,000 per carat for standard quality and up to $1.18 million for a pigeon blood ruby.
Renowned for its deep, velvety blue color and silky luster, Kashmir sapphire is also facing depletion of its mining industry, particularly in the Zanskar Valley. The latest record was set in early June 2025, when The Regent Kashmir, a 35.09-carat stone, was sold for $9.5 million.
The mountainous nature of the region, as well as the socio-political context and the lower yield of mining sites, are a real obstacle to the discovery of new stones, prompting professionals to turn to Ceylon.
Finally, the most renowned emeralds, with their intense green color, come mainly from Colombia, while others originate in Zambia, Zimbabwe, and Brazil. With only minor imperfections, prices reach dizzying heights, with the rarest stones fetching $305,000 per carat.
In short, the low number of new stones in the four main gemstones, coupled with high demand and the image of prestige still associated with them, have caused gemstone prices to skyrocket. But not all stones are out of reach: this is the case for those known as “fine” and “natural” stones.
The revenge of fine stones
It’s a fact: fine stones are gaining popularity. This phenomenon is accentuated by the depletion of traditional gemstones as well as the search for more affordable prices, both for professionals and individuals.
However, some of them, due to their appearance, brilliance, and color, are similar to traditional precious stones, becoming as desirable as, if not more desirable than, their cousins. And their prices are also rising.
Among them, spinel, which offers a wide range of colors, stands out. It can be red—the most expensive— and thus resemble ruby in both appearance and price, reaching several thousand dollars per carat. Offering a sublime pink color, Mahenge spinel comes from rare Burmese deposits. On the other hand, a mixture with other colors (orange, purple, or burgundy) has the effect of lowering its price.
The famous Paraiba tourmaline from Brazil is one of the few gemstones that is more expensive than diamonds. Found in sites with high concentrations of copper and manganese, it offers medium to high saturation, tending towards electric blue or intense lagoon blue, or even purple or green. Its price ranges from $150 to $15,500 per carat for a stone weighing 0.20 to 0.99 carats and from $550 to $30,000 per carat for a stone weighing 1 to 1.99 carats.
Shifting between three shades depending on the angle of view (intense blue, purplish pink, and yellow-green), Tanzanite (from Tanzania), discovered at the foot of Kilimanjaro, is also particularly sought after. Its price varies between $100 and $1,500 per carat.
Another stone with blue-green reflections, amazonite is also increasingly sought after. Believed to bring luck and fortune, amazonite is more affordable, costing between $20 and $50 per carat.
Overall, if these gemstones are increasingly popular with jewelers, it is because their price and, above all, their infinite range of colors open up a world of creative possibilities.
Invest, but not at any price
However, investing in precious stones, as in semi-precious stones, should not be taken lightly. Firstly, because their prices do not rise continuously, but in fits and starts depending on current events, demand, discoveries, and governmental instability at their extraction sites.
Secondly, because the price varies according to the type of stone and its rarity, but above all according to several characteristics that professionals summarize as the 4Cs.
It is therefore necessary to look at its weight or number of carats (the first C), bearing in mind that the larger a stone is, the rarer and therefore more expensive it is. Next, you need to check its size or Cut: a well-cut stone will maximize light reflection and therefore give it brilliance and sparkle, which will increase its price.
Purity or Clarity should not be taken lightly: a stone may contain external imperfections, but also internal ones, called inclusions, which can cause its price to drop.
Finally, the most obvious factor to consider for any stone is its color. It is understood that the more vivid and deep the color, the more sought-after it will be.
Whether you have a long-term investment or resale in mind, traceability is now key: a beautiful diamond must necessarily be accompanied by a GIA (Gemological Institute of America, the international reference laboratory for diamond certification). A colored stone must have a SSEF (Swiss Gemmological Institute) or at least a GRS (Gem Research Swisslab) certificate.
To avoid any mistakes, it is best to seek the assistance of a trusted jeweler, preferably a gemologist, in order to benefit from their knowledge of the intrinsic qualities of each stone. Only a professional of this caliber, such as Bonnot Paris, can help you make an informed choice based on your needs, preferences, and market conditions.
As an added bonus, such a professional is able to authenticate the stones, provide their certificates, and thus guarantee their resale value if necessary.
Read also > Investing in gold: why not?
Featured photo: Unsplash
