Diamond Price Index 2026: Live Market Performance & Historical Trends

Diamond Price Index 2026: What the Market Has Actually Done

As of September 7, 2026, the benchmark 1-carat natural round diamond — G-H-I color, VS1-SI1 clarity, Very Good cut or better — has a fair market price of $3,550. The lab-grown equivalent is $680. Every figure on this page is computed when the page loads, from our own daily tracked series.

Monthly Median, 1 ct Round Natural

Median of the daily observations in each month, in the mainstream quality band. Months our tracking did not cover are absent rather than estimated, and the observation count is shown so a thin month is obvious.

Our verified daily tracking begins 2025-03-11. We publish no index values before that date, because we did not collect them.

Year-to-Date Move by Shape (1 ct Natural)

Each shape measured against its own price a year-to-date ago, not against round.

Falling prices are shown in green because this is a buyer's guide: a decline is good news if you are buying. Marquise is excluded — at a held-constant quality band it inverts against round by 15–25%, which is a composition artifact rather than a real price.

Current Median by Carat Weight

Natural and Lab-Grown Are Diverging

The two markets are not moving together; the table above shows the current gap at each size.

Methodology & Sources

• What this measures: median listed prices from live retail inventory carried by our authorized US retail partners. We track listings, not completed sales — we have no visibility into what a stone finally transacted at, so nothing here is presented as transaction data.
• Median, not mean: every figure is a true median (the 50th percentile of the matched set), so a single premium outlier cannot pull the number upward.
• Matched quality band: prices are compared within a band (G-H color, VS2-SI1 clarity, Very Good cut or better for natural), never blended across the whole market. Blending produces artifacts such as one shape appearing to cost more than round purely because of what happens to be in stock.
• Minimum sample: a figure is published only when at least 20 listings back it. Below that the row is omitted rather than estimated.
• Coverage: our verified daily series begins 2025-03-11. We publish nothing before that date. Where the series has a gap, the gap is shown rather than interpolated.
• Recomputed on every page load, so what you are reading is today's data, not a figure typed in when the page was written.

Want a live estimate for a specification not shown here? Use the Diamond Price Calculator — it queries the same underlying dataset in real time.

Frequently Asked Questions

How often is the Diamond Price Index updated?

The underlying dataset refreshes daily. The figures on this page are recomputed every time it loads, so there is no publication cadence to wait for.

Why doesn't your index match Rapaport prices?

Rapaport prices reflect the wholesale market - what dealers pay for polished rounds ready for retail. Our index reflects what stones are listed at on the retail side. We do not see final sale prices, so we do not claim to know what consumers actually paid. We have not run a formal correlation against Rapaport for the current period, so we make no claim about how closely the two track; what we can state is our own figure. Absolute levels differ substantially, since Rapaport tracks dealer-to-dealer wholesale and we track retail listings (retail margin). Rapaport is the right index if you're a dealer; ours is the right index if you're a buyer.

Are diamond prices going up or down in 2026?

Down, across the board, but by very different amounts. On our tracked series every natural size we follow is lower year-to-date - roughly −18% at half a carat, −15% at one carat, and about −6% at three. The pattern is that larger stones are holding their value considerably better than small ones, not that any segment is rising. Lab-grown diamonds are declining across the board (-14% YTD at 1ct). See our full trend forecast in Diamond Price Trends 2026.

Which segment has held its value best?

Large natural stones. At three carats the year-to-date decline is roughly a third of what it is at half a carat, so bigger stones have held up considerably better - though "held up" here means falling less, not appreciating. Every natural size we track is lower year-to-date. That said, diamonds are not investments in the traditional sense - retail-to-resale spreads are 40-60%, so plan on 5-10 year hold periods before considering positive returns.

When will lab-grown prices stop falling?

We do not model production costs and will not guess at a floor. What the tracked series shows is that lab-grown has fallen steadily and faster than natural; where that stops is something we would be speculating about, so we don't. We would expect the market to reach by 2027-2028. That's another 25-30% below June 2026 levels. After that, prices should stabilize at approximately marginal cost plus a modest retail margin.

Should I wait for prices to drop further before buying?

Depends what you're buying. For lab-grown, the series has fallen steadily and shows no sign of flattening, so waiting has generally meant paying less - though we are describing what has happened, not forecasting what will. That only matters if you're willing to buy in a market where prices are still trending down. For natural under 1ct, another 3-5% may be extractable but the market has stabilized. For natural 1.5ct+, waiting risks paying more. See Best Time to Buy a Diamond in 2026 for the full timing framework.

Bottom Line: The 2026 Diamond Price Index Says…

Natural diamonds have stabilized. The 22-month decline is over for the benchmark 1ct, and the larger-carat segments are quietly recovering. Lab-grown continues its structural repricing - another 15-20% decline is likely before the market reaches marginal cost. The spread at 1 ct is wide and still widening: $3,550 for natural against $680 for a chemically identical lab-grown stone. We only have tracked data from 2025-03 onward, so we make no claim about whether that is a record. Neither is wrong; the choice depends entirely on what "diamond" means to you.

Ready to price your own specification? Use the Diamond Price Calculator for a live estimate against this index, or browse live retailer inventory to see the diamonds behind the numbers.