CaratShares Data · Updated daily
The Coloured Gemstone Index
The first continuously observable per-carat value series for fine coloured gemstones — aggregated from appraised, on-chain-recorded NAV across every stone listed on CaratShares. Free to cite with attribution.
| Species | Avg value / carat (USD) | Stones tracked |
|---|---|---|
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Methodology & status. Per-species value is the average of (appraised NAV × total facets ÷ carat weight) across listed stones; the composite is the unweighted mean of species values. Values are recorded by sworn appraisers with an on-chain audit trail. The series currently runs on the Base Sepolia testnet demo — stones and valuations shown are demonstration data, not investable assets; the mainnet series will begin with the first vaulted listings. Daily history accumulates from August 13, 2026.
Why this index exists
Every other major asset class has an observable price series. Coloured gemstones never did: transactions are private, auctions are semi-annual outliers, and appraisals are unpublished. This index is a first attempt at the missing benchmark — built on values that are recorded on-chain, revision by revision, rather than whispered between dealers. Read the background: Why coloured gemstones never had a public market · What a $30M ruby tells us about price discovery.