GEMIUS

The independent price reference for colored gemstones.

Buying or selling a colored gemstone?
Get a fair price.

Rubies, sapphires, emeralds: every colored stone.
Transparent, independent, free. We value stones. We don’t sell them.

Try free →Open app →See pricing
✓ 14 days of Premier free, no card✓ 20+ species · 15+ attributes

The logic is ours. The trail is yours.

The logic is ours. The trail is yours.

How GEMIUS works?

Attributes in, band out.

01

Describe your stone

Start with 4 core attributes, or upload a lab report. Unlock all 15+ for precision work at higher tiers.

02

Valuation engine triangulates

Cross-validated against taxonomy standards and live market signal.

03

Range returned

Defensible price band: narrows as you fill more attributes (±20% → ±10% → ±5%).

Who is it for?

First-time buyer to certified gemologist.
One engine, tighter bands as you fill more attributes.

Tier 0 · Free preview

The curious buyer

First-time. Am I overpaying? A ballpark without signing up.

Tier 1 · Pioneer

The collector

Hobbyist. 3–15 stones / year. Fast validation before writing a cheque.

Tier 2 · Professional

The trader

Jeweler / dealer. Defensible quotes in under a minute.

Tier 3 · Premier

The expert

Certified gemologist. Price bands with full attribute trail.

Validator + Valuator. One pass.

All other tools ask: what's it worth? GEMIUS asks two things at once: is the description gemmologically possible? and what's the market band? Inputs that violate dependency rules, Kashmir sapphire with a treatment that doesn't apply, a clarity grade impossible for that origin, surface a flag, not a price. Suspicious in, suspicious out: we'd rather decline than ship a number we can't stand behind.

The full Valuator lives on the webapp.

Try free →Open app →
Specimen
Sapphire
Pinned
OriginMyanmar (Burma)
ColorRoyal Blue
ClarityVS
CutCushion
Carat Range3.00 – 4.99 ct
TreatmentUnheated
Expected price per carat

$19,000 – $26,000

Floor6 of 15 attributesCeiling

More attributes tighten the range.

The Gemius Index

What is a colored gemstone worth?

A price index and a per-carat market band for 23 species, across four segments from Entry to Investor. Built on our taxonomy, vetted by gemologists, refreshed every quarter.

Show all 23 indicesShow fewer

Explore the catalogue

A profile and buyer guides for every species we cover.

Show all 23 speciesShow fewer

Taxonomy validated against

Cited gemological standards bodies. Among others.

GÜBELINSSEFGRSGIALMHCLOTUSAGLBELLEROPHONAIGSGIT