Coloured gemstones as an investment: a history of prices

The short version

Gems work, if you hold the right stones

Fine coloured gemstones have been one of the quiet success stories of the last few decades. But they are not a market where everything goes up. The stones that have performed are specific: untreated, top colour, from the origins the market prizes, with the right papers, bought at the right price, and held.

This guide walks through the real numbers: auction results, dealer prices and the only public price series in the coloured-stone world. We focus on the stones we deal in and believe in: ruby, sapphire and spinel first, with Paraíba and emerald alongside.

A scenario

Wealth you can carry in your pocket

Imagine an emergency: you have to leave quickly, or the things you rely on stop working. You cannot carry gold bars across a border, and you cannot walk out with piles of cash. But a single top 3 ct unheated Burmese “pigeon’s blood” ruby, in our experience, can be worth upwards of US$800,000, and it fits in a folded paper parcel.

That is what makes fine coloured stones such an unusual mix. They are rare and portable like nothing else, and unlike gold or cash you can also wear them and enjoy them every day. A stone like that can be a lifeline.

Gold weight at about US$4,300 an ounce (September 2026). 1 carat = 0.2 g. Always follow the customs rules of every country you travel through.

The big picture

How far prices have come

A handful of documented data points tell the story better than any chart. Each one is sourced below.

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Price history, gem by gem

There is no public stock ticker for gemstones, and the trade price guides are private. So we gathered every well-documented price point we could find: auction results (the exceptional stones, including the buyer’s premium) and dealer or wholesale prices (the trade level). The scale is logarithmic, so each gridline is ten times the one below. Hover or tap any point for the stone, its size and the source.

Size

Why size matters so much

Gem prices are quoted per carat, and the per-carat price climbs steeply with size because fine large stones are so much rarer. A 5 ct stone is not five times the price of a 1 ct. It can be many multiples more, per carat. Here is how Sotheby’s describes the ladder for Burmese pigeon’s blood ruby today:

The only public price series

The Gemfields numbers

What Gemfields is. Gemfields is a London- and Johannesburg-listed mining company. It runs two of the most important coloured-stone mines in the world: Kagem in Zambia, which it says supplies roughly a quarter of the world’s emeralds, and Montepuez in Mozambique, today the world’s leading source of ruby. Instead of selling privately, it sells its rough (uncut) production at auctions to invited cutters and dealers (over $1 billion each for emerald and ruby since the auctions began), and it publishes the results.1314

That makes Gemfields’ average price per carat the closest thing the coloured-stone world has to a public price index. Pick a series:

Treatment

Always choose unheated when you can

Most rubies and sapphires are heated to improve their colour and clarity. Well over 90% of sapphires on the market are treated.16 Heated stones are perfectly legitimate and have risen in price too. But unheated stones are rare, and in the last few years they have pulled away:

Our advice is simple: if the stone is meant to hold value, buy unheated whenever you can, and make sure a leading laboratory says so in writing.

Supply

Why fine stones keep rising

Gem prices are driven by a simple fact: the great deposits run out, and new ones rarely replace them with the same quality. The last 140 years in one timeline:

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Add the other drivers (the growing importance of origin and laboratory reports, strong demand from Asia, and the appeal of a store of wealth you can carry in your pocket) and you have a market where the finest goods are chased by far more buyers than there are stones.

Our view

Gem by gem

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The investment-grade checklist

This is what separates a stone that holds its value from one that doesn’t. Tick what applies to a stone you own or are considering:

Before you buy

The honest part

We believe in fine gemstones as a store of value, and we hold them ourselves. But we would rather you went in with open eyes:

• You buy at retail and sell at wholesale. That spread is why gems reward patience: the value has to grow past it. Consumer-protection guidance suggests planning to hold for ten years or more.25 Buy from a dealer, at a dealer’s price, and the gap is much smaller.
• Selling takes time. There is no exchange. Selling through a dealer or at auction takes weeks to months, and the major auction houses charge buyers a premium of roughly 27–28% on top of the hammer.26
• Quality decides everything. Commercial goods do not behave like fine goods. The price rises in this guide are for the top of the market.
• Not every stone sells well. Individual auction results vary. A stone the market doesn’t love can sell below its estimate. That is a comment on that stone, not on the market for fine goods.
• Papers protect you. Synthetics, glass-filled rubies and undisclosed treatments are the classic traps. A report from a leading lab removes almost all of that risk.27

This guide is for general information only and is not financial or investment advice. Past price movements do not guarantee future results. Figures are historical, in U.S. dollars, and come from the public sources listed below; auction figures include buyer’s premium. Please take independent advice before making investment decisions.