Rare earths are a set of 15 elements, called lanthanides, located near the bottom of the periodic table. Two other elements, scandium and yttrium, are also considered rare earth elements.
Astatine is a chemical element with the 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.
The 17 rare earth elements are: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), and yttrium (Y).
The Rare Earth (RE) elements include Y, La, and the Lanthanides (Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu). The chemistry of these elements is sufficiently similar that they can be treated as a group rather than individually.
Ununennium, or element 119, is a predicted chemical element. Its symbol is Uue. Ununennium and Uue are substitute names made by the IUPAC, (meaning "one-one-nine-ium" in Latin) until permanent names are made. Ununennium is the element with the smallest atomic number that has not been created yet.
Osmium, rhodium and iridium are probably the rarest metals found in the Earth's crust with average concentrations of 0.0001, 0.0002 and 0.0003 parts per million by weight respectively.
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.
Lithium, beryllium, and boron, despite their low atomic number, are rare because, although they are produced by nuclear fusion, they are destroyed by other reactions in the stars.
The rare earth elements (REE) are a set of seventeen metallic elements. These include the fifteen lanthanides on the periodic table plus scandium and yttrium.
Only 1-in-10,000 galaxies fall into the rarest category of all: ring galaxies.
Scientific element: Francium
The most expensive and second rarest natural element.
Hence, Lithium is not a rare earth mineral.
The rare earths are 17 metallic elements, located in the middle of the periodic table (atomic numbers 21, 39, and 57–71). These metals have unusual fluorescent, conductive, and magnetic properties—which make them very useful when alloyed, or mixed, in small quantities with more common metals such as iron.
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.
Ring galaxies are some of the rarest galaxies found throughout our universe, and for years scientists have scratched their heads, trying to figure out exactly how these galaxies came to be.
Can you name the hardest element? It's an element that occurs naturally in pure form and has a hardness of 10 on the Mohs scale. Chances are you have seen it. The hardest pure element is carbon in the form of a diamond.
Gold is rare throughout the Universe because it's a relatively hefty atom, consisting of 79 protons and 118 neutrons. That makes it hard to produce, even in the incredible heat and pressure of the 'chemical forges' of supernovae, the deaths of giant stars responsible for creating most chemical elements.
Platinum is 30 times more rare than gold. If all the platinum ever mined were melted and poured into an Olympic-sized pool, the platinum would barely reach your ankles. Gold, however, would fill three pools.
Rhodium, iridium and ruthenium are perhaps the rarest, roughly 1/5 as common as platinum. However, the sale price of rhodium is typically a bit less than that of platinum, and the rest are even less expensive because they are simply less useful.
Although the Earth's crust averages a mere 0.004 grams of gold per ton, commercial concentrations of gold are found in areas distributed widely over the globe. Gold occurs in association with ores of copper and lead, in quartz veins, in the gravel of stream beds, and with pyrites (iron sulfide).
Ununennium, also known as eka-francium or element 119, is the hypothetical chemical element with symbol Uue and atomic number 119. Ununennium and Uue are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon.
Iridium is one of the rarest elements on Earth. It is found uncombined in nature in sediments that were deposited by rivers. It is commercially recovered as a by-product of nickel refining. A very thin layer of iridium exists in the Earth's crust.
Rare. The abundance of tungsten in the Earth's crust is thought to be about 1.5 parts per million. Tungsten or Wolfram is considered to be one of the more rare elements.