How People Get Scammed Buying Diamonds (And How to Protect Yourself)

The Scams Are Getting Smarter

I repair jewelry every day. You wouldn't believe what people bring in thinking they own diamonds.

The scams have evolved. It's not just cubic zirconia anymore. Today's fakes are sophisticated enough to fool basic testing equipment - and most jewelry store employees.

Here's what you need to know.

Level 1: The Obvious Fakes (CZ and Crystal)

Cubic Zirconia is the classic fake. It's cheap, sparkly, and weighs more than a real diamond. To a trained eye, CZ looks "too perfect" - it lacks the subtle characteristics of natural stone.

Crystal and glass are even cheaper. They scratch easily and have visible bubbles or swirl marks inside.

These fakes are obvious to professionals but can fool consumers who've never held a real diamond. The problem? Most people have never held a real diamond before buying their first one.

Level 2: Moissanite Sold as Diamond

Here's where it gets interesting - and where I need to be clear about something first.

Moissanite is a legitimate gemstone - silicon carbide, originally from meteorites. It's beautiful, durable (9.25 on the Mohs scale), and has even more fire and brilliance than diamond. There's absolutely nothing wrong with moissanite - I work with it regularly and put the same craftsmanship into moissanite pieces as I do diamond.

When someone chooses moissanite intentionally, they're making a smart decision. You get a stunning stone with incredible sparkle at a fraction of the cost, with money left over for better metalwork or a more elaborate design.

The problem isn't moissanite. The problem is deception. Moissanite looks almost identical to diamond - even to jewelers. And it passes basic diamond testers. So when scammers sell moissanite as diamond, most buyers can't tell the difference.

Why Moissanite Passes the Beep Test

Those handheld diamond testers you see at mall stores? They measure electrical conductivity. Diamonds conduct heat in a specific way that most simulants don't.

But moissanite does.

So the mall guy waves his tester, it beeps, he says "yep, it's real!" and you walk away with a $200 stone you paid $2,000 for.

The Real Test: Double Refraction

Here's what the tester can't catch.

Moissanite is doubly refractive. When light enters the stone, it splits into two rays. Diamond is singly refractive - one ray.

Under a 10x loupe, look at the back facets through the table. In moissanite, you'll see doubled lines - like looking through a prism. Diamond shows single, crisp lines.

This is physics. It can't be faked.

The Torch Test (What I Use at My Bench)

Here's another definitive test: hit the stone with a jeweler's torch. Moissanite will temporarily turn yellow from the heat, then return to white as it cools.

Diamond? No color change. It just gets hot.

This won't help you at the mall, but if you bring a suspicious stone to a real jeweler, this is one way we can tell you exactly what you've got.

Level 3: Diamond-Coated Moissanite (The New Scam)

This one is genuinely clever and genuinely evil.

Take a moissanite, coat it with a thin layer of actual diamond material. Now you have:

• A stone that looks like a diamond
• Passes thermal conductivity tests (the surface IS diamond)
• Has the weight characteristics of moissanite

The coating is thin enough to be cost-effective but thick enough to fool basic testing.

How to catch it: The double refraction is still there underneath. And under magnification, you might see coating irregularities or edges where the coating meets the base stone.

This scam targets people who think they're being smart by using a diamond tester. They test it, it passes, they feel confident. That's exactly what the scammers want.

Lab vs Natural: How to Tell

This isn't a scam - lab diamonds are real diamonds. But you should know what you're buying.

Natural diamonds almost always have some inclusions. A flawless natural is incredibly rare and incredibly expensive. If someone's selling you a "flawless natural" at a suspiciously good price, be skeptical.

Lab diamonds tend to be very clean. Too clean can be a tell, but it's not definitive.

The certificate tells you:

• IGI = Almost always lab-grown
• GIA = Usually natural (though GIA now grades labs too)

Always ask for the certificate. No certificate = no proof of what you're buying.

What About "Diamond Testers"?

Let me be clear: basic diamond testers are nearly useless for identifying scams.

They test one property - thermal or electrical conductivity. They can tell you something ISN'T a diamond (like glass or CZ). They cannot reliably tell you something IS a diamond.

Moissanite passes. Coated stones pass. Some synthetics pass.

If someone's only verification is "it passed the tester," they don't actually know what they're looking at.

How to Protect Yourself

Before You Buy

1. Buy from reputable sources - Established jewelers with physical locations and reputations to protect
2. Demand certificates - GIA for naturals, IGI for labs. No cert = don't buy
3. Ask questions - If the seller can't explain double refraction or fluorescence, they don't know their product
4. Get suspicious of "deals" - If the price seems too good for the specs, it probably is
5. Request loupe inspection - A seller who won't let you examine the stone has something to hide

Red Flags

• No certificate or obscure certification labs
• Seller gets defensive about questions
• "Trust me" instead of education
• Can't explain basic diamond characteristics
• Price dramatically below market
• Only verification is a handheld tester beep

After You Buy

Get it independently appraised. Not by the store that sold it to you. By a certified gemologist who has no incentive to tell you what you want to hear.

It costs $50-100 for peace of mind. Worth it for any significant purchase.

Why This Matters

The diamond industry relies on consumer ignorance. The less you know, the easier you are to manipulate - whether that's selling you a scam or just overcharging for mediocre stones.

Education is protection.

The guy at the mall kiosk has a diamond tester and two weeks of training. He doesn't know double refraction from a disco ball. He knows how to make the machine beep and ring up the sale.

Find someone who actually knows stones. Someone who can explain what they're looking at and why. Someone who handles diamonds every day, not someone who just sells them.

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Think you might have been sold a fake? Bring it in or send photos - I'll tell you what you've actually got.