of my life. The setting was beautiful and the bride a clearly outof my league young doctor looked extremely hot. The only stressful part of the entire experience was buying the perfect engagement... See More
of my life. The setting was beautiful and the bride a clearly outof my league young doctor looked extremely hot. The only stressful part of the entire experience was buying the perfect engagement ring. Think about it. This is probably the most emotional purchase of your life. How do you know if you are really getting when you think you're buying. I look a a waiter. Or an undercover correspondent. Yes. To see how upfront dealers are I have agreed to wear a disguise so I can go undercover on the hunt for a ring. A little footnote here, finding a credible disguise can be tricky. Somebody like this is not going to be buying a diamond ring, ike a bear trap. We decide that stash is the way to go. For our undercover shopping test lookout producer erin is going to play my fictional girlfriend best friend. This woman will play the role of my supportive mom. She'll wear a camera, too. This woman is an internationally renown gem and jewelry expert. This is business in the front and partyn the back. I think this is the way to go. Very nice. Let's go back for a second. Look very carefully. The day before all of this dressup she explained to me something she says every shopper should be aware of. A little known industry practice that goes by the attractive name clarity enhancement through fracture filling. Manufacturers take a less desirable stone with naturally occurring cracks and through a high tech procedure the fill the cracks in with a led based paint. The old cracks disappear to the naked eye, becomes more attractive and looks like a higher grade diamond. It looks like a great diamond. It is at first glance. These fixed up diamonds typically sell for 50 to 30% less than untreated diamonds. There's nothing wrong with buying that. I know people who want bigger, more bang for the buck. But there's a problem. Sellers sometimes don't explain what it is and why it seems like you're getting a discount. Unfortunately there are jewelers who sell them without disclosure. In the gem and jewelry field we say in gems you get what you pay for or less. So we've decided to test how open dealers are about this. Our destination is new york city's diamond district. This is nellie's fine jewelry store where sales woman jenny shows us a diamond with an $8500 price tag. She says she can give it to us right on our budget for $3500. This is more like whole sale. You get a really good deal for diamonds. On the appraisal itself it's going to be $8500. That's the value of the diamond, how much it's really worth. Really? Worth $8500, huh. Sounds like an incredible deal. Soon jenny comes back with a store issued appraisal which i notice says natural ce diamonds. Will she explain to me what it is. There is a diamond, natural ce diamond. That is not true. Ce stands for clarity enhancement which has nothing to do with the prong. If you are sold a clarity enhanced diamond and don't know it, you must be in for a nasty surprise. This can happen if the stone is exposed to high heat during jewelry repair. The glass filler can melt right out of the crack. The dealer ought to tellou the stone needs to be removed before a jeweler works on the ring. And is there anything I need to know about, like care for this, this kind of diamond. Usually when you put lotion on your ring, diamonds absorb. So you bring it to us, free of charge and we clean it up for you. Okay then. I fork over 3 $500 in cash and she hands over the ring. Very nice. After our pho op jenny hands me this certificate where I spot a little asterisk next to the clarity grading noted as clarity enhanced. I saw the ce was clarity enhanced. Yes. What's that all about. I'm giving jenny another chance. Diamonds when they cut it and everything it's different. This particular one, this is how we call, one, like clarity enhanced. Basically it's not the way it was born. They make it beautiful. Sure, it does make the diamond more beautiful to the naked eye but jenny suggests it has to do with the quote unquote cutting and everything else, whatever that means. She makes no men of glass filled cracks. Thank you very much. Thank you. As we head down the street my undercover mom tells me this was not a fluke, it happens all the time all over the country. To find out exactly what is inside our brand new diamond, we take it to an independent lab for analysis. Here an x-ray florescent speck trom ter determines the competition. It has been clarity enhanced. The test shows a high led content glass was used to fill the stone's cracks. Those are pretty big cracks. Some are a little smaller like here, some a little larger. Nobody told me about that. It is part of the disclosure responsibility of the seller. H that news we hit the streets one more time and while jenny was vague about clarity enhancement, wait until you hear what this guy tells us. Hi, how are you? This is a shop called diamonds usa. It grows fast. My undercover mom told alex about our three grand budget and ipt in something around one krar et. I noticed on the paper holder it says clarity enhancement. I'll give you the certificate with it. No mention of clarity enhancement so I ask directly. What's clarity enhancement. That is the key moment right here. What will alex say. That is the polish they do to the stone. Polishing, wait a minute. That's not at all what clarity enhancement is but alex moves off the topic. That deals with how the facets are aligned. I ask him why is it such a good deal? Don't judge the price. Anything I should know about, special care or anything for this? Remember, clarity enhanced diamonds might not withstand repairs at high heat. Don't bang it. Nothing we should know about it though, nothing to be worried about. Don't be worried about anything. So I fork over the cash and later alex brings a certificate and a $9700 appraisal which makes our diamond looks like a bigger bargain. Whenever you want to clean is, she can just take a soft toothbrush. That's it. Really, that's it? We head out the door with your brand now ring and back at the studio. Down here it says feather filled, grades are based on appearance after clarity enhancement. Feather is another word for crack or fracture and here it says filled, doesn't say with what. For scientific confirmation we head back to the lab. It's been clarity enhanced. If it wasn't filled it would have been more in the imperfect range. The test shows it, too, was filled with a high content led glass. We now have scientific proof for two clarity enhanced stones. What about those mind boggling appraisals. We seek out a second opinion from a independent appraiser who calls himself the jewelry judge.
This transcript has been automatically generated and may not be 100% accurate.