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What’s Your Diamond Worth? “Worthless” Tenner Diamond Sells for Thousands

Check out how huge the Tenner Diamond is when held in your hand.

Last Updated on July 24, 2023 by Carla Jonas

$13.00 Diamond Ring Sells for Over $850,000

Earlier this summer, a diamond ring owner received the shock of a lifetime. Back in the 1980s, the anonymous buyer purchased what she thought was a worthless piece of costume jewelry for 10 British pounds. That’s just about $13 (US dollars), the estimated diamond worth. She was absolutely stunned when the Tenner diamond ring sold at Sotheby’s London auction house for well over $800,000.

The buyer, who asked to remain anonymous, purchased the diamond ring at a car-boot sale. This is where people go to sell unwanted stuff out their car trunks. After buying the seemingly junk jewelry, she spent decades wearing the ring while running errands and doing chores. She had no idea whatsoever, that the “cheap piece of glass” was actually a high-quality, huge real diamond.

What a gorgeous, flawless looking diamond.
What a gorgeous, flawless looking diamond.

The History of the Tenner Diamond

Before the ring was sold, Sotheby gave its take on why the buyer thought the ring was a worthless fake. The jewelry action house says the stone was cut in an old-fashioned style. It was also in a dark setting, with a silver mounting that had continuously tarnished over the years. This setting alone made the jewelry seem like it simply wasn’t real.

Because of the original, extremely low sale price of the diamond ring, Sotheby named it the “Tenner” diamond. This word means “ten-pound note” or in American terms, it’s slang for the “ten dollar bill.” That was close to the original estimated diamond worth.

One day, while the lady was wearing the ring, it was spotted on her finger by a local jeweler. The expert had a feeling the diamond was indeed real, and suggested the owner get an appraisal. So, she got the fake diamond ring appraised.

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The jeweler ended up being correct. Inside the old-fashioned, tarnished ring setting was a real, genuine diamond. It turned out to be a cushion-shaped gem of 26.29 carats in weight. According to the Gemological Institute of America, it has a clarity of VVS2 and an I color grading.

This now world-famous diamond dates back to the 19th century. However, no one knows the exact history of the diamond before the anonymous buyer purchased it back in the 80s. What we do know, is that she estimated the diamond worth at about $13.

Sotheby Sells Tenner Diamond for Over $850,000

The buyer paid about $13 for the diamond ring, which was probably purchased from the trunk of a car. During a Sotheby Fine Jewels sale held in London, France, it was purchased for $656,750 British pounds. Today, that’s a whopping amount of almost $857,000 (US dollars), the actual worth of the diamond and the ring setting.

The “worthless” diamond ring ended up being the top selling item of the day at the auction house. It beat its pre-sale estimated high by about $400,000. Apparently, the anonymous buyer isn’t the only who underestimated the diamond worth.

Sotheby identified the buyer of the Tenner diamond ring as simply “a member of the international trade.”

Diamond Worth - Check out how huge the Tenner Diamond is when held in your hand.
Check out how huge the Tenner Diamond is when held in your hand.

How Much Is Your Diamond Ring Worth?

No matter how large or small, everyone wants to know just how much their diamonds are worth. Figuring this out can be a bit complex. There are two factors that count:

  1. How much is the band’s metal setting worth?
  2. How much is the diamond inside the setting worth?
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Are you ready to buy a diamond? Well, be sure you receive your certificate of authentication. This assigns a grade to the gem, which is based on these four factors known as the 4Cs. All 4Cs are used to help determine diamond worth, and are as follows:

  • Color
  • Clarity
  • Cut
  • Carat

Although your gem may not be worth as much as the fabulous Tenner diamond, it does have value.

5 Tips to Determining Diamond Worth

A diamond’s quality is the main factor used in determining how much your diamond is worth. Use these five tips to help you assign value to your gem, much like the Tenner diamond was valued:

1. Figure Out the Gem’s Retail Market Value

Much like real estate, the value of a diamond depends on its comparables. Compare your gemstone to others with characteristics that are the same. Keep in mind that any inclusion can drastically change the gem’s value.

2. Determine the Value of the Band

Every diamond must be set inside some type of metal in order to create a ring. Typically, diamond rings are made using gold bands. This metal is measured using carats. 24K gold is not only the highest, it’s also 100% pure gold.

In most cases, 18K gold is used for making jewelry because it sturdier thank 24K. Because of this, most bands only go up to this high, which is 75% pure gold. The higher the carats, the more valuable the band.

3. Calculate the Numbers

Check this online diamond comparison guide. Fill out the fields of the diamond price calculator. For this exercise, let’s use:

  • Shape: Heart
  • Carat: 1
  • Color: E
  • Clarity: VS1

As you can see, this fictitious diamond’s worth is estimated to be about $7,425. Now, isn’t that nice?!?! Just keep in mind that depending on how you choose to sell your diamond, you can expect to get no less than 20% of that estimated value.

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Buy Diamond & Pearl Rings Online

When shopping for rings, take note of how amazing diamonds and pearls look together. Combining diamonds with AAA quality pearls will give you a ring with exceptional shine, sparkle and luster. Choose from Freshwater, Akoya, Hanadama, Tahitian, White South Sea and Golden South Sea pearl and diamond rings.

The Pearl Source has some amazing rings for just about every style. From pink pearls to peach pearls, from white pearls to black pearls, our gems come in various pearl colors to meet every fashion sense. And, we create customized pearl and diamond rings too!

Shop for Diamond & Pearl Rings Now

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