In terms of abundance in the Earth's crust, the rarest metals are: gold, platinum, osmium, iridium, palladium, ruthenium, rhodium, tellurium and rhenium. These metals are different from Rare Earth Elements, which aren't actually rare in terms of abundance, but are rarely found in concentrated ore deposits.
These include the fifteen lanthanides on the periodic table plus scandium and yttrium. Rare earth elements are an essential part of many high-tech devices.
In the light REEs category, neodymium has the highest number of uses. For one, you can use it on mobile phones, medical equipment, and electric cars. It's the best rare metal for making permanent magnets. Neodymium magnets are strong and highly useful when weight and space are limiting factors.
Platinum. If you think gold is a rare metal, our metal of the month is even scarcer: 30 times rarer than gold, in fact. Platinum, unlike most other metals, is difficult to find among the minerals in the Earth's outer crust.
Gold vs Diamonds: Rarity
So which is rarer, gold or diamonds? Gold is rarer than diamonds, despite what the diamond industry would have you believe. The diamond industry is very good at marketing, portraying diamonds as luxurious, rare gemstones, and increasing diamond prices.
Gold and platinum definitely count as contenders for the number one spot. Silver may be more useful industrially, but it is somewhat less rare, so less precious. Rhodium, iridium and ruthenium are perhaps the rarest, roughly 1/5 as common as platinum.
Tungsten
Tungsten, which is Swedish for "heavy stone," is the strongest metal in the world. It was identified as a new element in 1781. It is commonly used to make bullets and missiles, metal evaporation work, manufacturing of paints, creating electron and Television tubes, and making glass to metal seals.
Neodymium is not found in the earth's crust as a free element but in the minerals monazite and bastnaesite. It is a solid metal at room temperature with a melting point of 1024°c and a boiling point of 3074°c.
Looking farther into the future, other sources claim that things like aluminum might run dry in about 80 years. Other studies indicate that rhodium, followed by gold, platinum and tellurium, are some of the rarest elements in terms of their percentage in the planet's crust and their importance to society.
Astatine is a chemical element; it has symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours.
Neodymium magnets are the strongest magnets available! The strength of a magnetic field is measured in BHmax (maximum energy product). The higher the BHmax, the higher the strength. For example, a samarium magnet has a BHmax of 24, and a neodymium magnet has a BHmax of 40.
Tantalum, a rare, very hard transition metal, does not occur naturally in metallic form. The estimated average abundance of tantalum in Earth's crust is about 2 parts per million (or 0.0002%).
The most expensive natural element is francium. Although francium occurs naturally, it decays so quickly that it cannot be collected for use. Only a few atoms of francium have been produced commercially, so if you wanted to produce 100 grams of francium, you could expect to pay a few billion U.S. dollars for it.
The current price of Rhodium is $162.50 per gram.
Please note that the price provided above is the retail price for private investors and is aligned with industry retail pricing.
Platinum, palladium, and rhodium are rarer than gold. Iridium, osmium and ruthenium are even rarer than the other three.
The rarest mineral on Earth is kyawthuite. Only one crystal, found in the Mogok region of Myanmar, is known to exist. Caltech's mineral database describes it as a small (1.61-karat) deep orange gemstone that the International Mineralogical Association officially recognized in 2015.
RHODIUM: TOP MOST VALUABLE METAL
Rhodium is the most valuable metal and exists within the platinum group of metals. It is used in jewelry for a final finish on white gold jewelry. It occurs in the very same ore in which gold and silver exist – only, in smaller quantities.
The elements range in crustal abundance from cerium, the 25th most abundant element of the 78 common elements in the Earth's crust at 60 parts per million, to thulium and lutetium, the least abundant rare-earth elements at about 0.5 part per million.
Investing in a market well ahead of the mainstream public has its advantages, particularly when that investment centers on scarce commodities and emerging technologies. But it also comes with the kinds of risks unique to any emerging market or industry. So be careful. Rare earth metals fit well within this category.
Rhodium: Earth's Rarest and Most Expensive Precious Metal.
Iridium-containing ores are found in South Africa and Alaska, U.S., as well as in Myanmar (Burma), Brazil, Russia, and Australia. In the late 20th century South Africa was the world's major producer of iridium.
Painite : Not just the rarest gemstone, but also the rarest mineral on earth, Painite holds the Guinness World Record for it. After its discovery in the year 1951, there existed only 2 specimens of Painite for the next many decades. By the year 2004, there were less than 2 dozens known gemstones.