Helps protect the air we breathe – PRICE: $37/gram
Rhodium, with its ability to increase the hardness of various materials, is something of a wonder metal. It is valuable to glass manufacturers as well as in producing automobiles, where it is used extensively in catalytic converters to change harmful pollutants into nontoxic gases, such as nitrogen and carbon dioxide.
Rare noble metal is a laboratory staple – PRICE: $51/gram
Every year, suppliers are able to extract just a few hundred tons of this rare and very useful precious metal. A noble metal, it is highly nonreactive, making it resistant to corrosion and many chemicals, even at high temperatures. Consequently, platinum is widely used as a catalyst, as well as to make laboratory, medical and dental equipment. (More about Platinum)
Investors’ safe haven – PRICE: $55/gram
In financial crises, the precious metal becomes a coveted investment, driving its already-lofty prices even higher. But it’s also used for industrial purposes and to make jewelry. More than 188,800 tons have been mined so far, leaving around 56,000 tons in the Earth. (Read Story of Gold)
Rare isotope stockpiles dwindling – PRICE: $2,000/gram
Helium-3 occurs when radioactive tritium decays. It is attractive to scientists for its potential use in developing clean nuclear-fusion energy, but unfortunately, helium-3 occurs naturally on Earth only rarely; since 1989, NASA has been exploring the possibility of extracting the gas from the moon’s surface, where it is deposited by solar wind. (Read Could Helium-3 really solve Earth’s energy problems?)
Rare red crystal is made in America – PRICE: $10,000/gram
Red beryl is so rare that it has only been discovered in a few places in the world, primarily in mines in the states of Utah and New Mexico. The sturdy crystal, which is used in making jewelry, is slightly softer than diamond, but much rarer. The beryls are a group of minerals that are colorless in their pure form, but become tinted when they contain impurities. Though most tinting results in green or blue crystals — emeralds and aquamarines — the scarce red beryl owes its distinctive coloring to iron, chromium, calcium and manganese.
Has a silver lining – PRICE: $10,900/gram
Radioactive plutonium may have a bad reputation, but it is indispensable to scientists. It is notoriously used in fuel rods for nuclear reactors, but plutonium also provides fuel for satellites, which need an efficient energy source for the long distances that they travel. Plutonium batteries also are powering Voyager 1 – the space probe that has traveled the farthest through our solar system — and may keep it going until 2025.
Explosive isotope makes watches hands glow – PRICE: $30,000/gram
If the hands on your watch glow In the dark, you own a tiny bit of the radioactive isotope tritium. A superheavy type of hydrogen made in nuclear reactors, tritium is also a key component of hydrogen bombs. But there’s no need to get rid of your watch — because its beta rays are too weak to penetrate human skin by themselves, tritium is only a health hazard if it is inhaled or swallowed.
The hardest material on Earth – PRICE: $210,000/gram
The hardness of a mineral is measured by the Mohs scale; diamonds, with a score of 10, are at the top of the chart. Formed by tremendous pressure in the Earth’s interior, diamonds are the planet’s hardest material and are quite plentiful. Their durability makes them particularly useful for industrial applications, which is where some 70 percent of all diamonds end up each year, in tools like dentists drills and ultrafine saws. Diamonds are priced according to the “Four C’s”: color, clarity, cut and weight (in carats). Large, flawless diamonds are typically the most expensive, because they are much more rare. (Read 10 Facts About Diamonds You Should Know)
Radioactive element finds gold in space – PRICE: $27 million/gram
Californium (atomic number 98) is a man-made element created when scientists bombard the chemical element curium with alpha particles; the resulting element is a radioactive material. Ten known versions, or isotopes, exist and can be used to treat certain forms of cancer and to detect gold and silver in ore or oil at the bottom of a well. Although californium is artificially made on Earth, certain stars that explode as super-novae may produce it in space.
Particle accelerators make supermatter – PRICE: $100 trillion/gram
Antimatter — essentially a mirror image of existing matter — is very difficult to make: Physicists can create it only in the world’s largest particle accelerator, the Large Hadron Collider, near Geneva, Switzerland. So far, only about a billionth of a gram of the extremely rare material can be made per year. It is so scarce, in fact, that its potential uses are still largely unexplored. One field in which antimatter shows some possibility of practical application is in treating cancer. Researchers have found that antimatter directed at tumors is highly effective in destroying cancer cells, although clinical use is still a long way off. (Read Antimatter Facts: Top 10 Things You didn’t Know About Antimatter)