The State of the Diamond Market in 2025: Prices, Trends & What’s Next

The global diamond market in 2025 is going through one of its most complex transitions in decades. From falling polished diamond prices to the rapid expansion of lab-grown diamonds and a long-term decline in natural diamond supply, the industry is being reshaped before our eyes.

Whether you’re a buyer, retailer, or just a jewellery lover, understanding these changes is key to making smart decisions. Here’s a breakdown of the latest diamond industry trends 2025 that came out of Paul Zimnisky's August 2025 report and what they mean for the future of diamonds.

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Polished Diamond Prices: Still Under Pressure

Polished diamond prices in 2025 have faced continued pressure. The Zimnisky Global Rough Diamond Index shows that demand recovery hasn’t been uniform, with certain cuts and sizes holding value more strongly than others. The good news? For buyers, this means more approachable entry points into the market - especially for classic round brilliant diamonds, which remain the benchmark shape.

For the trade, the focus is on margin: jewellers are being selective about what they stock, leaning into evergreen demand (round, oval, and emerald cuts), moving away from slower movers and focusing on a 'virtual sale' in-store and online.

Rough vs. Polished: The Price Gap

- Rough diamond prices remain more volatile compared to polished.

- Mining companies have adjusted production, which can create disconnects between rough supply and polished demand.

- The gap often determines how much pricing flexibility jewellers have at retail - an important detail for anyone considering a diamond purchase this year.

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Lab-Grown Diamond Prices 2025

Lab-grown diamond prices in 2025 continue their downward trend, particularly in larger sizes. Wholesale markets show significant price compression, making lab-grown options more affordable than ever.

For consumers, this widening price gap between natural and lab-grown diamonds means lab-grown engagement rings offer larger size-for-price value. Jewellers, however, are adjusting: positioning lab-grown as an accessible luxury rather than a like-for-like substitute for natural.

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Natural Diamond Supply 2025

Natural diamond supply in 2025 is forecast to tighten gradually. Several legacy mines are reaching maturity, and few large-scale new projects are scheduled to offset the decline. This isn’t an immediate “shortage” story, but it does suggest natural diamond rarity is likely to increase over the long term.

For buyers, that means natural stones still hold strong emotional and heritage value — not as an “investment,” but as a symbol tied to legacy and scarcity.

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FAQ: Diamond Prices and Trends in 2025

Are diamond prices going up in 2025?
Overall, polished diamond prices remain under pressure, though specific cuts and sizes are more resilient.

Is now a good time to buy a diamond?
Yes - but not because diamonds are an “investment”. The current market allows buyers to access higher-quality stones at more approachable price points which gives them time to shop around and prioritise what matters. 

Why are lab-grown diamond prices falling?
Increasing supply, improved production efficiency, and broader competition are driving down wholesale costs.

Will natural diamond supply eventually decline?
Yes, but very gradually. Several key mines are winding down, with limited new projects in development.

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Final Thoughts

The diamond market in 2025 is dynamic, shaped by evolving consumer preferences and shifts in supply. Whether you’re drawn to the heritage and rarity of natural stones or the accessibility of lab-grown, it’s a year of choice and opportunity for buyers looking to make meaningful jewellery purchases.  

If you are curious about how these trends might affect your own diamond selection, contact me to talk through options tailored to your style and budget.