What this page is. There is no public transaction record of lab grown diamond resales, and this page does not claim one. What can be measured honestly is listing-price history: how retailers have repriced the same certified stones over time, and how quickly stones leave the market. That history is the best public context for what a lab grown diamond might be worth later.

Same-stone repricing, April to September 2026

Tracking identical certified stones (same certificate number, same retailer) listed in both April and September 2026. Attribution basis: this comparison covers the 3 tracked US retailers whose public listings carry third-party certificate numbers (Brilliant Earth, Grown Brilliance, Ritani); retailers without published certificate numbers cannot be stone-matched and are not part of this statistic.

Of the 266,838 certified stones tracked in April, 78% no longer appeared in the September 2026 listings of the 3 certificate-carrying retailers above (sold, delisted, or moved to a retailer outside this panel; public data cannot distinguish which). The figures in the strip above cover the five months from April to September 2026.

Because these are the same physical stones at the same retailers, this comparison is free of the inventory-mix distortion that affects month-to-month median charts.

Pooled listing-price history (1 carat round)

Each month pools only retailers with at least 30 qualifying listings that month.

Coverage note. June 2026 was a partial collection cycle for Ritani; June rows pool fewer Ritani listings than adjacent months.

Composition caveat. Pooled medians move with inventory mix as well as price; the same-stone repricing figures above are the cleaner signal.

What this means for resale value

Falling new-stone listing prices compress what any reseller can expect: a buyer can compare a resale offer against a brand-new certified equivalent in seconds. The honest summary of the data above: new-listing prices for the same stones have been drifting down, and any resale estimate should be anchored to current new-listing prices, not the original purchase price. This page presents listing-price history and delisting behavior only; it does not report resale transactions and makes no promise about resale proceeds.

Stat definition. Figures on this page pool all qualifying listings in the stated carat range: all colors, clarities, and cut grades, from retailers with at least 30 qualifying listings. The monthly Index benchmark is a different, tighter statistic (E VS1 round Excellent-cut IGI). The two are not comparable and should not be quoted against each other.

Loose stones only. Every figure on this page is for a loose lab grown diamond as listed, before any ring setting. No blended ring-total pricing appears on this page; setting costs vary by retailer and are never merged into these comparisons.