Gemstone market index — price per carat by origin

Ruby$11,800+1.4%Sapphire$86,000-0.4%Sapphire$11,500+1.8%Emerald$34,000+1.3%Emerald$13,200+2.6%Paraíba Tourmaline$42,000+4.7%Paraíba Tourmaline$13,000+3.1%Spinel$6,200+0.6%Cobalt Spinel$21,000+5.2%

01 / INDEX

Dove sono i prezzi, e cosa li determina

IN DIRETTA

STONE	2-3 CT	3-5 CT	5-10 CT	CHG
Ruby, no heat Montepuez, Mozambique	$7,500	$11,800	$18,400	+1.4%	Vedi tutto
Sapphire, no heat Kashmir	$58,000	$86,000	$135,000	-0.4%	Vedi tutto
Sapphire, no heat Sri Lanka	$6,800	$11,500	$19,800	+1.8%	Vedi tutto
Emerald, no oil Muzo, Colombia	$22,000	$34,000	$52,000	+1.3%	Vedi tutto
Emerald, no oil Kagem, Zambia	$8,600	$13,200	$19,500	+2.6%	Vedi tutto
Paraíba Tourmaline Paraíba, Brazil	$28,000	$42,000	$60,000	+4.7%	Vedi tutto
Paraíba Tourmaline Mozambique	$8,500	$13,000	$18,000	+3.1%	Vedi tutto
Spinel, no heat Mahenge, Tanzania	$3,800	$6,200	$9,800	+0.6%	Vedi tutto
Cobalt Spinel Luc Yen, Vietnam	$14,200	$21,000	—	+5.2%	Vedi tutto

Indicative mid-market reference for fine-quality untreated material, compiled from published 2026 trade price guides and auction results. Ranges in this market are extremely wide: fine unheated ruby of top colour is quoted anywhere from $15,000 to over $100,000 per carat, and Kashmir sapphire from $50,000 to beyond $200,000, depending on colour, clarity and certification. These figures describe the middle of the fine-grade band and are a reference to check a listing against, not a quotation. CGX will publish its own index from cleared trades once volume supports it.

02 / PERFORMANCE

Perché le pietre preziose mantengono valore

Ruby Sapphire Emerald

INDEX · BASE 100

+31 / +47%

10Y

+71 / +116%

15Y

+124 / +217%

20Y

+194 / +366%

Illustrative index modelled on published trade estimates of 4–8% average annual appreciation. Not a forecast, and not investment advice.

03 / PRICING

The four C’s, and the two that matter more

Colour, clarity, cut and carat are the traditional four. In coloured stones they do not carry equal weight — colour dominates, and origin and treatment can move a price by a multiple rather than a percentage.

COLOUR

The dominant driver

Hue, saturation and tone together account for more of a fine stone’s price than any other factor. The step from good to fine colour can triple the per-carat figure.

TREATMENT

The dividing line

Roughly 95% of ruby and sapphire in trade is heat treated, and virtually all emerald is oiled. Certified untreated stones trade at two to five times heated equivalents.

ORIGIN

A multiplier, not a label

The same stone with a Kashmir origin report can be worth several times its origin-undetermined price. Within ruby, a Montepuez origin report commands a clear premium over origin-undetermined material of equal grade.

WEIGHT

Non-linear

Price per carat accelerates with size. Fine untreated stones become dramatically scarcer above 3 carats, and the market prices that scarcity directly.

CERTIFICATION

Where value is proven

GRS, SSEF, Gübelin and AGL reports establish species, treatment and origin. On stones where those findings carry the price, the report is part of the asset.

CLARITY

Judged by species

Eye-clean is expected in blue sapphire. In emerald, inclusions are normal and graded against the species, not against diamond standards.

04 / READING THE INDEX

What these numbers are, and what they are not

A REFERENCE

Mid-market, per carat

Each figure is an indicative mid-market price per carat for fine material of that species and origin, in that carat band, with no treatment and a top-tier origin report. It is a point to measure a specific stone against, not a quotation for any stone.

NOT A QUOTATION

Individual stones vary widely

Two stones of identical weight and origin can differ by a multiple. Colour saturation, the presence or absence of a window, the cutting, and clarity all move a price far further than the carat band alone suggests.

WHERE IT COMES FROM

Published trade sources

Compiled from published price guides, auction results and dealer surveys. As volume on the exchange builds, CGEMX will publish its own index from cleared trades, which is the only genuinely reliable basis for a reference price.

05 / WHY ORIGIN MOVES PRICE

The same stone, two reports, two prices

Origin is the single largest multiplier in coloured stones, and the reason a laboratory report from a top-tier house is worth what it costs.

SCARCITY OF SOURCE

Some deposits no longer produce

A closed mine sets a hard ceiling on supply, and the market prices accordingly.

01Kashmir sapphire. The original workings were effectively exhausted by the early 1890s. Every Kashmir stone traded today was mined more than a century ago.

02Muzo and Chivor emerald. Still producing, but fine untreated material in larger sizes appears rarely and is absorbed quickly.

03Brazilian Paraíba. The Batalha mine that defined the category is largely worked out; Mozambican material supplies most of the current market at a fraction of the price.

GEOLOGY

Chemistry differs by deposit

Trace elements determine colour and fluorescence, and laboratories can read them.

01Iron content suppresses fluorescence in ruby. Low-iron material glows under daylight; high-iron material reads flatter in the same colour range.

02Copper is what makes Paraíba tourmaline neon, and its presence is what a report certifies.

03Inclusion patterns are effectively a fingerprint of the deposit, and are how origin is determined at all.

FOR DEALERS

Measure a stone against the index before you buy

Every listing on the exchange shows its price per carat alongside the asking price. Signed in, your holdings are plotted against these benchmarks directly, so you can see at a glance which of your stones sit above the reference and which sit below.

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