Monthly Diamond Market Update – October 2025

Welcome to our monthly column dedicated to the diamond market. Each month, we analyze the key global trends, the most significant events, and the dynamics that shape demand, pricing, and commercial strategies. Drawing on reputable sources such as Rapaport News, IDEX, and other specialized channels, we provide an always up-to-date, accurate, and reliable overview.

General trend

October 2025 presented a mixed picture across the major global markets. In the United States, luxury retail remains solid ahead of the holiday season, with stable sales and renewed consumer confidence. Europe is experiencing gradual consolidation, supported by the revival of international tourism in luxury shopping capitals and a renewed interest in diamonds as a safe-haven asset. Major groups such as LVMH and Kering continue to report growth in the jewelry segment, although caution remains high due to geopolitical tensions and the economic slowdown in the Eurozone; as a result, many market players are prioritizing higher-quality stones and certified traceability.

In Asia, India’s manufacturing sector slowed down following the Diwali holiday closures. Ongoing negotiations between the U.S. and India over reciprocal tariffs (expected at 15–16%) are moving toward a potential agreement that could stabilize the international supply chain.

Demand remains polarized: smaller diamonds (below 1.20 ct) continue to feel the pressure of high supply, while stones of 2 carats and above, along with elongated fancy cuts (Marquise, Oval, Long Cushion), performed markedly better, trading at prices 20–25% higher than traditional cuts.

Price trends

Let’s take a closer look at price movements, which in October showed signs of stabilization, with slight declines across most categories.

According to Rapaport data, the RapNet Diamond Index (RAPI™) for 1-carat round diamonds (color D–H, clarity IF–VS2) fell by 1.7%, a more moderate drop compared to previous months. Smaller categories, however, saw sharper declines: –4.4% for 0.30-carat diamonds and –2.8% for 0.50-carat stones.

Higher-carat stones continue to prove more resilient: the RAPI for 3-carat diamonds rose by 0.3%, while excellent-quality 5-carat round gems (D–E, IF) posted increases of up to 4%.

The IDEX Polished Price Index also showed a slight decline of –0.48%, indicating a market entering a consolidation phase after the summer volatility linked to reciprocal tariffs between the United States and India. Daily movements remained limited, with only two brief fluctuations at the beginning and end of the month.

At a category level, round diamonds between 0.50 and 1.99 carats showed a general downward trend in higher grades (G+ and VS1+), while fancy cuts recorded more pronounced declines. According to IDEX, price drops outnumbered increases by more than three to one, with the sharpest corrections concentrated in the 1–2 carat range within mid-to-high color and clarity categories.

Overall, October appears to have marked a phase of normalization after the more pronounced movements of previous months: a more stable yet still selective market, in which quality and rarity remain the key drivers supporting price resilience.

The impossible diamond: half pink, half colorless

From Botswana’s Karowe mine (the same site that made headlines just a month ago for the discovery of the gigantic Motswedi) comes a new find destined to enter history: a 37.41-carat rough diamond whose two halves are completely different - one a delicate pink, the other perfectly colorless - separated by a sharp, natural line.

No known precedent exists for such a gem. Pink diamonds account for less than one-tenth of one percent of all stones extracted, and after the closure of Australia’s Argyle mine in 2020, they have become nearly impossible to source. In this case, the unique combination of hue and transparency reveals an exceptionally rare geological balance: insufficient pressure would have left the crystal colorless, while excessive pressure would have turned it entirely colored.

A genuine scientific breakthrough from the University of Tokyo

On October 29, a team of researchers at the University of Tokyo announced a discovery set to change the history of materials science: for the first time, they managed to create nanodiamonds without relying on extreme temperatures or pressures, but by using electron beams. The results, published in Science, open extraordinary new avenues for research: the transformation of carbon takes place at room temperature, producing flawless diamonds just a few nanometers in diameter.

Beyond its impact on materials research, this technique could revolutionize electron microscopy and the production of components for quantum computing, while at the same time protecting the most delicate organic substances from radiation damage. According to the researchers, similar mechanisms may also explain the natural formation of diamonds in meteorites or uranium-rich rocks, offering a new perspective on the geological processes of our planet and deep space. Yet another demonstration of how diamonds continue to bridge science, nature, and wonder.

Emerald cut conquers Hollywood: Joe Manganiello’s engagement

On October 17, at the San Diego Film Festival, actor Joe Manganiello—known for his roles in True Blood and Magic Mike, as well as his previous marriage to Sofía Vergara—officially announced his engagement to actress and television host Caitlin O’Connor.

What captured the attention of the jewelry world was above all the ring chosen by Manganiello: an emerald-cut diamond set on a thin platinum band, a design that blends old-Hollywood elegance with modern, refined taste. This cut, defined by wide step-like facets, highlights the gem’s purity and transparency more than its brilliance, showcasing every internal detail of the stone. For this reason, the emerald cut is regarded as a choice of great awareness and balance, reserved for diamonds of truly exceptional quality.

O’Connor’s ring has already inspired numerous designers and international maisons, confirming the return of the emerald cut as a symbol of understated yet absolute elegance - a refined tribute to the diamond’s inner light and, perhaps, to the strength of the bond it represents.

Conclusions

October 2025 reaffirms the diamond’s role as a stable point of reference in a complex economic environment: a tangible asset capable of preserving value and meaning over time. For some, it is an investment; for others, an emotional legacy to safeguard and pass on. In every case, understanding its potential correctly is the first step toward managing it with confidence.

Auctentic offers a discreet, transparent, and personalized approach for those who wish to understand and enhance their assets with the same care reserved for the things that truly matter. Request a confidential appraisal of your diamonds or jewelry and discover how to turn their value into new opportunities, guided by our expert gemologists.

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