Neodymium is a chemical element1. Its official symbol is Nd, and its atomic number2 is 60, which means it has 60 protons in its nucleus.
The element was discovered by Austrian chemist3 Baron Carl Auervon Welsbach in a roundabout way. Welsbach’s original elemental ‘discovery’ was didymium – a material he thought was an element. It even had the symbol Di in Mendeleev’s 1869 version of the periodic table of elements. Welsbach later separated the material into two elements4 – neodymium and praseodymium. The name neodymium comes from the Greek word neos (meaning new) and didymos (meaning twin). Praseodymium means green twin. The elements are so similar that they are next to each other on the periodic table.
Rare-earth elements
Neodymium is one of the 17 elements known as rare-earth elements. The rare-earth elements occur together on the periodic table5. Fifteen of the elements, numbered 57–71, are in the row that sits under the main table. (This row is also called the lanthanide series6.) Two more elements – scandium and yttrium – have similar chemical properties so they are also called rare-earth elements.
The rare-earth elements aren’t really all that rare. In the 18th and 19th centuries, materials were called ‘earths’ if they could not be changed further by heating them up. ‘Earths’ like magnesium were relatively easy to find. The rare-earth elements are dispersed or ‘sprinkled’ in ore7 deposits, rather than occurring as free elements or concentrated in minerals. At the time, they were difficult to locate so they were considered rare.
Neodymium is fairly common – it’s about as abundant as zinc and copper8. However, it is dispersed throughout the Earth’s crust9, with small amounts found here and there. Neodymium, like most rare-earth elements, is often a byproduct10 from other mining operations. If it is found with other rare-earth elements that are chemically similar, it becomes a complex process and a considerable expense to separate them. In 2019, a metric ton of neodymium oxide11 costs more than NZ$160,000! Compare that to NZ$4,000 for zinc and NZ$10,000 for copper. In spite of the price, neodymium and other rare-earth elements are in huge demand.
Uses of neodymium
Neodymium compounds were first used to colour glass. Its properties cause the colour of the glass to change from purple to yellow to blue or green under different lighting conditions12. We still use neodymium compounds in glass products today – to whiten the light in incandescent13 bulbs and to make goggles for welders and glass blowers.
The real demands for neodymium are in products likely to be found in your pocket and throughout the classroom. Neodymium, iron14 and boron (NIB) combine to create very powerful magnets15. A 1 g NIB magnet can hold up a 1.3 kg iron sphere! Tiny NIB magnets are found in cell phones, earbuds, computer hard drives and DVD and CD players. Larger NIB magnets are used in the electric motors of hybrid16 and electric vehicles and in some wind turbines. NIB magnets are also used to identify counterfeit money. Real paper money has tiny magnetic particles added to the inks when they are printed.
NIB magnets and toys
Neodymium magnets are exceptionally strong. They have a very strong attraction to one another and can move considerable distances and at great speed. There are reports that people have had fingers crushed when caught between two magnets.
Magnetic building sets with rods and balls have been redesigned to make them safer to use. The tiny, strong neodymium magnets make the building sets lots of fun, but if the magnets come loose, they can be dangerous if swallowed. The magnets attract each other and can cause tears in the stomach17 and intestines.
Nature of Technology
Rare-earth elements are difficult to mine and process. Their production requires careful management to minimise the associated environmental hazards. Only a few countries mine and process rare-earth elements. As the demand grows, supply has – at times – become a political issue.
One solution is to recover and reuse rare-earth materials from cell18 phones, hard drives and other electronic devices. The technology to recycle rare-earth materials is becoming more efficient and cost-effective. This will allow the materials to be processed on much larger scales.
Related collection
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Useful links
Rare opportunity to recycle rare earths discusses some of the issues and technology involved with rare-earth production and recycling.
Rare earths statistics and information provides statistics and information on the worldwide supply of, demand for, and flow of the mineral19 commodity group rare earths – scandium, yttrium and the lanthanides from the U.S. Geological Survey website.
Read about the history and future of rare earth elements from the Science History Institute.
- element: A substance made of atoms that all have the same atomic number. Elements cannot be split into simpler substances using normal chemical methods.
- atomic number: The number of protons in the nucleus of an atom. This determines an element’s properties and location on the periodic table of elements.
- chemist: A scientist trained in the science of chemistry. Chemists study the composition of matter and its properties.
- element: A substance made of atoms that all have the same atomic number. Elements cannot be split into simpler substances using normal chemical methods.
- periodic table: The organisation of all known elements into groups with similar properties.
- lanthanide: A series of 15 chemically related elements on the periodic table of elements with atomic numbers from 57 (lanthanum) to 71 (lutetium).
- ore: Rock or sediment from which we can extract elements and minerals.
- copper: A transition metal in Group 11 of the periodic table – symbol Cu, atomic number 29.
- crust: The outermost layer of the Earth. Estimated to be between 5–50 km thick. Made of solid rock of all types (metamorphic, igneous and sedimentary).
- byproduct: A secondary product produced during manufacturing, mining or refining. Something unexpected or unintended caused as a result of something else.
- oxide: A chemical compound made up of oxygen combined with at least one other element. Most of the Earth’s crust consists of oxides.
- condition: An existing state or situation; a mode or state of being.
- incandescent: Light produced as a result of heating or combustion. For example, the filament in an electric light bulb glows white hot when a suitable electric current passes through it.
- iron: A chemical element with the symbol Fe.
- magnet: An object that generates a magnetic field that can influence magnetic objects such as iron and other metals.
- hybrid: The progeny of cross-breeding 2 pure-breeding lines.
- stomach: An organ of digestion with a sac-like shape located between the oesophagus and the small intestine. It temporarily stores food, mixes and churns it with gastric juice and allows digestion of some of the protein content of food to take place.
- cell: 1. Building block of the body. A human is made of millions of cells, which are adapted for different functions and can reproduce themselves exactly. 2. A simple electrolytic device that enables chemical energy to be transformed into electrical energy.
- mineral: 1. (Geology) A naturally occurring solid formed through geological processes. Any given mineral has a characteristic chemical composition and a specific set of physical properties. 2. (Dietary) An inorganic compound needed for proper body function and maintenance of health, for example, iron in the form of haeme present in red meat.