10 of the World’s Rarest Gemstones

There are roughly 200 varieties of natural gemstone known in the world today. Alongside the world’s precious gems (diamond, ruby, sapphire, and emerald) are numerous semi-precious stones, some of which are so incredibly rare that their value outstrips many of the world's most valuable precious gems. Here are a few of the rarest from around the world.

1. TANZANITE // FOUND ONLY IN TANZANIA


 
Tanzanite is a beautiful blue variety of the mineral zoisite, and is so named because it is only found in a small area near the foot of Mount Kilimanjaro in Tanzania. The stone was not discovered in commercial quantities until the 1960s and since then its popularity has grown tremendously, thanks largely to the efforts of Tiffany & Co. Heat-treating tanzanite at very high temperatures can improve the blue coloration, so most gems on the market have been treated in this way, but any tanzanite that has not been heat-treated and has a strong blue color naturally will be of a much higher value. Because it is only found in one small location, the value of tanzanite looks likely to soar over time; once those mines have been emptied there will be no new stones coming onto the market—unless a new source is found.

2. BLACK OPAL // THE DARKER THE BETTER


Daniel Mekis via Wikimedia Commons // CC BY-SA 3.0

 
Opals are usually a creamy-white color and are made special by the rainbow-colored inclusions that reflect the light as the stone is moved. Black opals are much rarer, because almost all of them are found in mines in the Lightning Ridge area of New South Wales in Australia. The darker their background color and brighter the inclusions, the more valuable the stone. One of the most valuable black opals of all time is the "Aurora Australis," which was uncovered in Lightning Ridge in 1938. The 180-carat opal is especially admired due to its large size and intense harlequin coloration; in 2005 it was valued at AUS $1,000,000, or about $763,000 U.S.

3. LARIMAR // ONLY FOUND IN THE DOMINICAN REPUBLIC


Wikimedia Commons // Public domain

 
Larimar is a very rare blue variety of the mineral pectolite and is found in only one small area of the Dominican Republic. This turquoise stone’s name was created by the man who brought the stone to prominence in 1974, Miguel Méndez—he took the first part of his daughter’s name, Larissa, and combined it with the Spanish word for sea, mar, to create the portmanteau larimar. Locals had known of the existence of the stone for generations, because small examples had washed up on the seashore, but it was not until the 1970s that sufficient quantities were found in the ground to open a mine.

4. PARAIBA TOURMALINE // NEON LUSTER


DonGuennie (G-Empire The World Of Gems) via Wikimedia Commons // CC BY-SA 4.0

 
Tourmalines are common in many colors across Brazil, but the Paraiba tourmalines are the only stones with a bright turquoise hue, thanks to their copper content. The very rare gems were discovered in 1987 by determined miner Heitor Dimas Barbosa, who had been driven by a belief that something special lurked under the hills of the Brazilian state of Paraiba. Barbosa was right, and after years of fruitless digging, he finally unearthed a tourmaline of unrivaled neon blue that set the gem market alight. The extremely rare stone (only one stone is mined for every 10,000 diamonds) then became intensely sought-after. In 2003 very similar turquoise-colored tourmalines were found at mines in the mountains of Nigeria and Mozambique, although some say they are not quite as striking as the Paraiba tourmaline.

5. GRANDIDERITE // ONE EXCEPTIONAL EXAMPLE


DonGuennie (G-Empire The World Of Gems) via Wikimedia Commons // CC BY-SA 3.0

 
Grandiderite was first described in 1902 by French mineralogist Alfred Lacroix, who found it in Madagascar and named it in honor of the French explorer Alfred Grandidier, an expert on Madagascan natural history. This extremely rare blue-green mineral has been found in a number of places around the world, but so far only Madagascar and Sri Lanka have produced any gem-quality stones, and these are still extremely scant. The majority of the known stones are translucent, but the most rare, and therefore most valuable, example ever found was transparent. In fact, the stone was initially assumed to be another rare gem, serendibite, because grandiderite of that color and transparency had yet to be seen. The gem was only identified as grandiderite after expert analysis and was subsequently sold for an undisclosed sum. It’s safe to assume that if a gem of similar quality were to be unearthed, its scarcity alone would ensure it fetched an extremely high price.

6. ALEXANDRITE // COLOR-SHIFTING GEM


 
The amazing color-changing stone alexandrite was discovered in 1830 in the Ural Mountains in Russia and named after Russian tsar Alexander II. A variety of chrysoberyl, the stone’s remarkable color-shifting capability makes it especially sought-after: In sunlight the stone looks blue-green, but under incandescent light it becomes red-purple. The degree of color change varies from stone to stone, with some only showing marginal change, but the most valuable are clear stones that demonstrate complete color change.

Although some large examples of the stone have been found (the Smithsonian houses the world’s largest known cut sample of alexandrite at 65.08 carats), the majority are under one carat. This means that the value of a gem under a carat may only be $15,000, but a stone larger than one carat might fetch as much as $70,000 per carat.

7. BENITOITE // STATE GEM OF CALIFORNIA


Pablo Alberto Salguero Quiles via Wikimedia // CC BY-SA 3.0

 
Benitoite is only mined in one small area of California, near the San Benito River (hence the name), but the mine closed for commercial mining in 2006, making this gemstone yet more scarce. The gem was first identified around 1907 by geologist George Louderback and has a deep-blue color that shows especially interesting qualities when caught under UV light, when it glows fluorescent. The gem was named the official state gemstone of California in 1985 in recognition of the fact that, despite it being found in trace quantities in Arkansas as well as Japan and Australia, California is the only place where it can feasibly be mined. Due to the rarity of discovering a good quality benitoite of a reasonable size, it can fetch huge prices on the open market—a well-cut benitoite stone at over 2 carats can fetch more than $10,000 a carat.

8. PAINITE // ONCE THE WORLD’S RAREST GEM


Rob Lavinsky via Wikimedia // CC BY-SA 3.0

 
Painite was first discovered by British gemologist Arthur Charles Davy Pain in 1951 and recognized as a new mineral in 1957. For many years only one specimen of the dark red crystal was in existence, housed at the British Museum in London, making it the world’s rarest gemstone. Later on other specimens were discovered, although by 2004 there were still fewer than two dozen known painite gems. However, in recent years a couple of mines in Myanmar have begun to produce some painite, and there are now said to be over 1000 stones known. The scarcity of this gem has made it extremely valuable and just one carat can fetch more than $60,000.

9. RED BERYL // TINY AND SCARCE


Didier Descouens via Wikimedia Commons // CC BY-SA 3.0

 
Red beryl, also known as bixbite or red emerald, is so rare it is estimated by the Utah Geological Survey that a single such gem is uncovered for every 150,000 gem-quality diamonds. Pure beryl is colorless and only gains its bright hues from impurities in the rock: chromium and vanadium give beryl a green color resulting in an emerald; iron provides a blue or yellow tint creating aquamarine and golden beryl; and manganese adds the deep-red color to create red beryl. Red beryl is only found in Utah, New Mexico, and Mexico, and the majority of examples found are just a few millimeters in length, too small to be cut and faceted for use. Those that have been cut are generally less than a carat in weight, and a red beryl of 2 or 3 carats would be considered exceptional.

10. TAAFFEITE // DISCOVERED BY CHANCE


DonGuennie (G-Empire The World Of Gems) via Wikimedia Commons // CC BY-SA 3.0

 
Austrian-Irish gemologist Count Edward Charles Richard Taaffe bought a box of cut stones from a jeweler in Dublin in the 1940s, thinking he had purchased a collection of spinels. But on closer inspection, he noted that one of the pale mauve gems was not reacting to the light in the same way as the rest of the spinels, so he sent it off to be analyzed. The results revealed that he had discovered a hitherto unknown gemstone—a serendipitous but frustrating situation, since he had discovered a cut gem and had no idea where the mineral naturally occurred. Fortunately, once the new stone had been announced, many other collectors re-examined their own spinel collections and a number of other samples were uncovered. Finally the source of the stone was tracked down to Sri Lanka, although a handful have also been found in Tanzania and China. It is thought that less than 50 examples of taaffeite exist—many of which are housed in geological and private collections, making this gemstone so rare the ordinary public are unlikely to ever encounter it.

The ChopBox Smart Cutting Board Has a Food Scale, Timer, and Knife Sharper Built Right Into It

ChopBox
ChopBox

When it comes to furnishing your kitchen with all of the appliances necessary to cook night in and night out, you’ll probably find yourself running out of counter space in a hurry. The ChopBox, which is available on Indiegogo and dubs itself “The World’s First Smart Cutting Board,” looks to fix that by cramming a bunch of kitchen necessities right into one cutting board.

In addition to giving you a knife-resistant bamboo surface to slice and dice on, the ChopBox features a built-in digital scale that weighs up to 6.6 pounds of food, a nine-hour kitchen timer, and two knife sharpeners. It also sports a groove on its surface to catch any liquid runoff that may be produced by the food and has a second pull-out cutting board that doubles as a serving tray.

There’s a 254nm UVC light featured on the board, which the company says “is guaranteed to kill 99.99% of germs and bacteria" after a minute of exposure. If you’re more of a traditionalist when it comes to cleanliness, the ChopBox is completely waterproof (but not dishwasher-safe) so you can wash and scrub to your heart’s content without worry. 

According to the company, a single one-hour charge will give you 30 days of battery life, and can be recharged through a Micro USB port.

The ChopBox reached its $10,000 crowdfunding goal just 10 minutes after launching its campaign, but you can still contribute at different tiers. Once it’s officially released, the ChopBox will retail for $200, but you can get one for $100 if you pledge now. You can purchase the ChopBox on Indiegogo here.

Mental Floss has affiliate relationships with certain retailers and may receive a small percentage of any sale. But we choose all products independently and only get commission on items you buy and don't return, so we're only happy if you're happy. Thanks for helping us pay the bills!

12 Smart and Simple Kitchen Hacks

Merlas/iStock via Getty Images Plus
Merlas/iStock via Getty Images Plus

Use these quick and simple tricks to save time in the kitchen and make cooking easier—and safer.

1. Put a damp paper towel under your cutting board.

Take a paper towel, wet it, wring it out, and place it under your cutting board. This will keep the board from slipping all over your counter and allow you to cut more safely. You can put a damp paper towel under mixing bowls to keep them from sliding around, too.

2. Use cooking spray on your cheese grater.

A person using a cheese grater
Whichever way you have your grater positioned, a little cooking spray will make the job easier.
vinicef/iStock via Getty Images Plus

Before you start grating cheese, lay your grater down on its side, which keeps it from moving around and catches all of your cheese in once place. Then spray the surface with the cooking spray of your choice. The oil lubricates the surface and makes grating easier, especially for sticky cheeses.

3. Put felt glides under countertop appliances.

Not only will this save your countertops from getting scratched, but it also makes oft-used appliances easier to move when you need them.

4. Put a spoon on top of boiling pasta water.

A person holding a spoon with penne pasta over a pot of boiling water.
Foam be gone!
Andrii Pohranychnyi/iStock via Getty Images Plus

Does the foam of your starchy pasta water boil right up out of the pot? There’s a simple fix: Lay a metal or wooden spoon over the top of the pot. According to Gizmodo, this method works because the foam is “thermodynamically unstable," so when the foam’s bubbles reach the spoon, they burst, "breaking the layer of foam and sending all the bubbles collapsing down again.” If you opt for metal, though, make sure to use oven mitts to remove it from the top of the pot—it will be hot.

5. Keep dental floss handy.

You can use it to cut soft cheeses. “If the cheese is small, you can hold it in one hand while your other pulls the floss taught and does the cutting,” cheesemonger Nora Singley writes at The Kitchn. “For larger situations, place cheese on a surface, shimmy the floss beneath it, and simply slice up, holding both ends of the floss and crossing the two ends to complete the cut. Then repeat in equal intervals.”

You can also use non-minty dental floss to cut cookie dough, burritos, and hard-boiled eggs; slice melons and layers of cake; to tie things together; and get food unstuck from baking sheets.

6. Preheat your baking sheet.

A baking sheet in the oven.
Pre-heating your baking sheet saves time.
allanswart/iStock via Getty Images Plus

If you’re making something like French fries or roasted veggies and your baking sheet is hot right from the get-go, you won’t have to go through the process of flipping your food later. Plus, both side of your food will be evenly browned and cook faster.

7. Save burnt pans with a dryer sheet.

Have you charred a pan so badly that the food you're trying to cook essentially became a part of the pan? Before you throw the pan out, try tossing in a dryer sheet, adding warm water, and letting it soak for 15 to 20 minutes. Then wash with soap and water as usual, and the burned bits will come right off. Karen Lo at Food52 writes that “It feels like an absolute miracle—because it is. But, according to lifestyle reporter Anna De Souza, it’s also ‘likely the conditioning properties of the dryer sheet’ that do the trick.” If the burn is really bad, Lo says you can use two dryer sheets and hot water for severe cases if you’d like, and let it soak overnight—use your judgment.

8. Leave the root end on your onion when cutting it.

A person holding an onion by the root end and dicing an onion with a knife.
Leaving the root end of your onion on gives you something to hold onto while you're dicing.
andreygonchar/iStock via Getty Images Plus

This method is a game changer: It allows you to dice your onions safely and quickly. First, according to Real Simple, you should cut the top off of the onion; then lay the onion on the now-flat top and cut the vegetable in half through the root. Next, peel off the skin, being careful to leave the root attached. Take half of the onion and lay it, flat side down, on the cutting board. Holding on to the root end, slice the onion vertically in strips of your desired size, without cutting through to the root. Then slice in the opposite direction to dice. When you’re done, save the root end of the onion to make stock.

9. Use a Bundt pan when cutting corn.

When you’re cutting corn on a flat surface, the kernels tend to fly everywhere messily. But if you hold the ear of corn—pointy end down—on the center of a Bundt cake pan, then rotate as you cut, the kernels will fall neatly into the pan.

10. Put away your potato peeler and use this method instead.

A pot of boiling water with potatoes.
dashtik/iStock via Getty Images Plus

Peeling potatoes is time-consuming and wastes delicious potato. Instead, use this potato peeling hack from Foody Tube: Make a small cut into the skin around the circumference of the potato, then boil it. Once the potato is cooked, peel the skin off. It’s that easy.

11. Keep your plastic wrap in the fridge.

When it’s cold, plastic wrap is easier to handle and less likely to get stuck to itself.

If getting plastic wrap to stick is the issue, wet the rim of whatever you’re trying to cover before putting on the plastic. The water will help it cling to the surface.

12. Use magnets to hold down parchment paper.

Two rolls of parchment paper on a white surface.
Keep parchment paper from rolling up on your baking sheet with this clever trick.
Viktoriia Oleinichenko/iStock via Getty Images Plus

To keep parchment paper from rolling up on baking sheets—and therefore making it incredibly difficult actually to put anything on the sheet to cook—Le Cordon Bleu-educated pastry chef Amy Dieschbourg uses magnets to hold the paper in place. Once everything is on the paper, remove the magnets and get cooking.