Rubbish Check
CNBC Top News · 26 September 2026
source“Supply glut, lab-grown alternatives: What’s behind the fall of diamond prices to record lows”
R2/ 10
Lightly altered
Rubbish Rating — 1 = base fact, 10 = pure rubbish
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In short
Rubbish Talk rates CNBC's headline on diamond prices hitting record lows a 2/10 because both named causes, oversupply and lab-grown competition, are directly attributed to primary-source data and an industry executive quoted in the piece.
The Verdict
Base fact, lightly altered. The headline compresses a multi-cause story into two words ("supply glut, lab-grown alternatives"), but both causes are exactly what the article's own sourcing, Diamond Standard's CEO and Rapaport pricing data, identifies as the drivers. The only soft spot is folding a niche investment-grade index's all-time low together with the separate, much larger decline in retail natural-diamond prices, but the article itself does this too, so it's not a headline-specific distortion.
What actually happened
Natural diamond prices have fallen sharply since 2021, driven by a post-Covid overproduction glut and a consumer shift toward cheaper lab-grown stones. The Diamond Standard Index, which tracks investment-grade diamonds, hit its lowest-ever level in early August 2026. Miners including De Beers are now cutting supply, closing or pausing mines, in an attempt to stabilise prices.
Key facts
- A 1-carat natural diamond now averages $3,898, down 51% from $8,007 in 2021, per Rapaport Group data cited in the article.
- The Diamond Standard Index hit 2,490 in early August, its lowest level ever, before recovering slightly to just above 2,500.
- Independent Rapaport releases corroborate the natural-diamond squeeze: the 1-carat RAPI fell 9.9% in 2025 alone, with smaller stones down over 20%, largely attributed to synthetic competition and oversupply.
- A comparable lab-grown stone sells for as little as $450 versus $2,800 to $3,200 for a natural equivalent of the same specs, per Brilliant Earth data in the article.
- Engagement rings with lab-grown centre stones hit 61% of sales in 2025, up 239% since 2020, per The Knot's 2026 Real Weddings Study.
- De Beers halted production at its Venetia mine for over two years in July, and at least two other mines filed for bankruptcy in 2026.
What to watch for
- Whether De Beers' Venetia halt and other mine closures actually reverse prices, or merely slow the decline, since Diamond Standard's CEO calls it "the beginning of a recovery" but offers no hard forward data yet.
- Whether the lab-grown share of engagement ring sales keeps climbing past 61%, which would further pressure natural stone prices regardless of supply cuts.
- Watch for Rapaport's monthly RAPI updates to see if the "record low" framing holds or if 2026 shows the moderation already visible in January's data.
About this scoreThe R-Score is Rubbish Talk's editorial opinion on how far a headline's framing sits from what the underlying facts support. It is a judgement about presentation and emphasis, not an allegation that any outlet has acted dishonestly. Every figure we rely on is linked under Receipts so you can check it yourself.
