Diamond Watcher

Diamond Price Index

Q: How do you calculate these prices?

Each month, we pull real listings for a fixed set of shapes (round, oval, cushion) and carat points (0.5–3ct), all at color G / clarity VS1, and record the median price per retailer for each combination.

Q: Why do some prices show fewer retailers?

Not every retailer has matching inventory for every spec every month. Cells averaged across fewer retailers than the full set are marked with a dashed border or an asterisk, so you can tell a well-supported number from a thin one instead of treating every average as equally reliable.

Q: Why do diamond prices vary between retailers?

The same certified diamond can be listed thousands of dollars apart at two different retailers — markup, sourcing, exclusivity arrangements, and return policies all play a role. See our full breakdown on the blog. Why Does the Same Diamond Cost More at Different Retailers?: https://blog.diamondwatcher.com/why-does-the-same-diamond-cost-more-at-different-retailers/

Q: What's the difference between natural and lab-grown diamonds?

Lab-grown diamonds have the same chemical composition and physical properties as natural diamonds — the real difference is origin. Natural diamonds form over billions of years underground; lab-grown diamonds are grown in a controlled lab environment over weeks to months. Natural vs. Lab-Grown Diamonds: A Complete Buyer's Comparison: https://www.diamondwatcher.com/compare/natural-vs-lab-grown

Q: Why is the natural vs. lab-grown price gap so large?

Lab-grown diamonds can be produced in far greater volume without mining, removing the rarity and extraction costs that drive natural diamond pricing. That's exactly what the gap at the top of this page measures — recalculated every month across all four tracked retailers.

Q: How often is this updated?

Once a month. Each month gets its own permanent report — see Past reports below to browse previous months.

Report for August 2026

Diamond prices vary wildly between retailers for the exact same stone. Every month, we track real listings across major retailers for a fixed set of shapes and carats — so you can see who's actually cheaper, and exactly how much less lab-grown diamonds cost than natural ones.

Not enough data yet

The monthly price snapshot hasn't collected both natural and lab-grown listings for the same spec yet — check back after the next snapshot.

Price grid — shape × carat

Median price, natural diamonds, color G / clarity VS1 — dashed cells are averaged from fewer than 4 retailers

Retailer comparison

Round, 1ct, G / VS1, natural

RitaniBlue NileRare CaratBrilliance

Natural vs. lab-grown premium

How much more natural costs than lab-grown, by shape (1ct, G / VS1)

Need both natural and lab-grown listings at this carat to compare.

The 1-carat price cliff

Round, natural, G / VS1 — median price by displayed carat weight

Not enough listings around the 1ct mark yet — check back after next month's run.

Frequently Asked Questions

How do you calculate these prices?▼

Why do some prices show fewer retailers?▼

Why do diamond prices vary between retailers?▼

What's the difference between natural and lab-grown diamonds?▼

Why is the natural vs. lab-grown price gap so large?▼

How often is this updated?▼

Ready to find your own 1ct Round?

Search live inventory across Ritani, Blue Nile, Rare Carat, and Brilliance — filtered to the exact shape, carat, and quality you're comparing above.

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Diamond Price Index

Price grid — shape × carat

Retailer comparison

Natural vs. lab-grown premium

The 1-carat price cliff

Frequently Asked Questions

Past reports

Diamond Education

Retailer Ratings

Guides & About Us

Comparisons