A free handbook for anyone buying Colombian emeralds — one stone or a parcel. It covers what decides value, what the trade does not volunteer, what things actually cost, and the specific ways buyers lose money. No registration, no email required.

What this book is

Most emerald guidance online is written by people selling emeralds, and reads like it. This one is too — we sell them. So rather than ask you to trust us, it is written to be useful even if you buy from someone else, and it says plainly where our interests and yours diverge.

It is a buyer’s handbook. It is not investment advice, it does not tell you emeralds will appreciate, and it makes no offer of participation in any venture. What it does is explain how the market prices this stone, so you can judge a quote on your own.

Chapter 1

What an emerald actually is

Emerald is beryl — the same mineral family as aquamarine — coloured green by traces of chromium and vanadium. Remove those and you have a colourless crystal worth very little. The entire value of the stone rests on a trace impurity.

It forms under pressure in hydrothermal veins, and it forms fractured. Those fractures, and the mineral inclusions the trade calls the jardin — the garden — are not defects in the way a flaw in a diamond is a defect. They are how you know the stone grew in the ground rather than in a laboratory.

A flawless emerald at an ordinary price is the single most reliable warning sign in this market. Nature rarely makes them. Factories do.

Emerald sits around 7.5 to 8 on the Mohs hardness scale, which sounds robust. Hardness and toughness are different properties, and emerald’s internal fractures make it far more prone to chipping than that number suggests. This matters for how you wear it and how you clean it.

Chapter 2

What decides the price

Five variables move independently, and one of them dominates.

Of these, saturation is the lever. A vivid stone can be worth several times an otherwise identical stone that is merely good. A pale two-carat emerald can be worth less in total than a vivid one-carat emerald. If you remember one sentence from this book, remember that one.

It also means per-carat figures are close to meaningless in isolation. You cannot value your stone by dividing someone else’s total by their carat weight, because their stone was a different colour and a different size and the curve is not flat. Detail: what drives the price.

Chapter 3

Treatment — the thing the trade does not volunteer

Almost every emerald you will ever be offered has been treated. Fractures that reach the surface are filled — traditionally with cedarwood oil, more recently with polymer resins — so they scatter less light and become far less visible. Nothing about the colour changes. It is a clarity treatment, and it is largely reversible.

This is centuries-old normal practice and it is not a scandal. Concealing it is.

Laboratories differ slightly in wording — GIA uses four levels, others add a step below minor — so read the report you actually have. Treat a one-step disagreement between reputable labs as normal.

Why this matters after you buy

• Never put a filled emerald in an ultrasonic cleaner. It strips filler faster than anything else in a jewellery shop.
• No steam, no heat, no solvents. Warm water, mild soap, soft brush.
• Filler can be replaced. Re-oiling is routine work for a competent bench jeweller. Degraded polymer resin is a specialist job, which is the practical argument for preferring oil where you have the choice.
• A closed bezel protects a fissured stone better than open claws.

In the United States this is not merely etiquette. The FTC’s Jewelry Guides require disclosure of treatments that are impermanent, that create special care requirements, or that materially affect value. Emerald fracture filling meets all three tests. Plenty of sellers still bury it. Detail: oil grades explained.

Chapter 4

Origin, and what it is actually worth

Colombian material commands a premium over comparable stones from Zambia or Brazil. Some of that is earned — the classic Colombian green is a genuinely distinct look — and some is reputation.

• Muzo — the historic benchmark. Warm, slightly yellowish green at high saturation.
• Chivor — cooler and bluish. Often cleaner at comparable size.
• Coscuez — enormous production across the whole quality range.
• La Pita — fine material since the 1990s, sometimes sold as Muzo goods.

Origin determination is inference, not certainty. Laboratories compare trace chemistry and inclusion profiles against reference material. Colombian emeralds characteristically show three-phase inclusions — a cavity holding gas, liquid and a solid crystal together — which is why country of origin is usually determinable with confidence while individual mine attribution is much harder.

A mine name on a laboratory report is a well-supported opinion. A mine name with no report behind it is a sales claim.

One term worth knowing: gota de aceite, “drop of oil”, describes a soft roiled texture in the finest Muzo material that raises value substantially. It has nothing to do with oil treatment, which lowers it. The overlap in language causes real confusion, and occasionally it is deliberate.

Chapter 5

How to verify what you are holding

Work in this order with a 10x loupe and one point of light.

1. Look at colour with your eyes first. Perfectly uniform colour is a flag; natural stones almost always show zoning.
2. Find the inclusions. If you find none at all, be suspicious rather than pleased.
3. Hunt for round bubbles. Perfectly spherical bubbles mean glass. Nature does not make them in beryl.
4. Rock the stone and watch the fractures. Flashes of orange, yellow or blue are filler. A little is normal. Flashes everywhere mean you are buying filler.
5. Look through the table at the back facets. Obvious doubling means it is not emerald — peridot doubles strongly.
6. Check the girdle and profile for the join line of a composite.
7. Weigh the price against what you just saw. The mismatch is usually the real tell.

Tests that do not work

What a laboratory can do that you cannot: separate natural from synthetic, measure the degree of enhancement, and offer an origin opinion. What a report does not do is value the stone — grading and appraisal are separate services, and an appraisal written by your seller is marketing. Detail: how to tell if an emerald is real.

Chapter 6

Where the money actually goes

This is the chapter most seller-written guides leave out.

Emerald is not a liquid asset. There is no spot price, no exchange, and no daily quote. Every transaction is negotiated against a stone that is unique, which means the spread between what a dealer pays and what a retail buyer pays is wide — far wider than in gold, where a published spot price anchors everyone.

What that means in practice

• You will not resell at retail. If you buy at a retail counter and sell to a dealer, you are crossing that spread in the expensive direction. This is the single most common way private buyers lose money on coloured stones.
• Documentation is most of your liquidity. A stone with a laboratory report and an invoice stating treatment sells faster and higher than an identical stone without, because the next buyer does not have to re-verify it at their own cost.
• The premium sizes are the liquid ones. Very small stones are commodity goods; very large fine stones have a thin buyer pool. The middle moves.
• Treated stones are not an investment story. A heavily oiled stone is a beautiful object bought at a fair price. It is not scarce.

If you want an asset with a published price and a same-day buyer, buy bullion. Emerald is bought because someone wants that specific stone.

We say this as a seller of emeralds because the alternative — letting you discover it at resale — is how this trade earned its reputation.

Chapter 7

Four ways into the market

We suggest rough first for anyone new. There is no treatment to disclose, synthetic emerald is grown to be cut rather than to imitate rough, and what you are judging is physical rather than a description you are being asked to trust. Detail: buying rough emerald and the trade guide.

Chapter 8

How buyers lose money

1. Buying on a photograph taken under a spotlight. Hard directional light flatters every stone. Ask for diffuse daylight-balanced light and video.
2. Accepting a mine name with no report. You are paying an origin premium for an unsupported claim.
3. Not establishing treatment before paying. The single most expensive omission in this market.
4. Comparing quotes that are not comparable. Two stones matching on carat weight can be entirely different goods.
5. Buying ‘certified’ from an unnamed laboratory. If no lab is named, there is no report.
6. Cleaning it wrong. One trip through an ultrasonic cleaner can undo the clarity you paid for.
7. Assuming retail price is resale value. See chapter six.

Chapter 9

The buyer’s checklist

Before money moves, you should have all of this in writing:

• Carat weight and dimensions in millimetres
• Colour description — hue, tone, saturation
• Degree of clarity enhancement, and which filler
• Origin, and whether it is a laboratory opinion or a seller’s claim
• The laboratory report in full, with a report number you can verify on that laboratory’s own site
• Whether the stone has been re-oiled since it was graded
• A returns window long enough to have it independently checked

A seller who answers all seven without hesitating has examined the stone. One who cannot has not.

Where to go next

Everything in this book is expanded on the site, free and without registration: the full library · how we grade · loose stones · rough and specimen.

Questions about a specific stone: 888-296-4870, Monday to Friday, 9am–6pm Central.

This handbook is educational. It is not investment advice, not an appraisal, and not an offer of participation in any venture. MultiGen Minerals sells physical stones; nothing here should be read as a claim that any stone will appreciate.