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Rare Earth Elements (REE) Gems

 

 

Rare Earth Element minerals (also referred to as "REE minerals") are minerals that contain at least one of the fifteen chemical elements in the periodic table known as the lanthanides, as well as scandium (Sc) and yttrium (Y). Scandium and yttrium are not lanthanides but are considered to be rare earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties. The lanthanide series of chemical elements comprises the fifteen metallic elements with atomic numbers from 57 (lanthanum) through 71 (lutetium). The fifteen lanthanides are (in order of atomic number starting from the lowest): 57 lanthanum (La), 58 cerium (Ce), 59 praseodymium (Pr), 60 neodymium (Nd), 61 promethium (Pm), 62 samarium (Sm), 63 europium (Eu), 64 gadolinium (Gd), 65 terbium (Tb), 66 dysprosium (Dy), 67 holmium (Ho), 68 erbium (Er), 69 thulium (Tm), 70 ytterbium (Yb) and 71 lutetium (Lu). Click here for more detailed information on the lanthanides near the bottom of this page.

The term "rare earth element" is somewhat outdated as these elements are not particularily rare nor are they "earths". "Earths" is an obsolete mineralogical term referring to "water-insoluble, strongly basic oxides of electropositive metals incapable of being smelted into metal" (using late 18th century technology). The REE elements certainly are not rare. Cerium is the most abundant lanthanide and is the 26th most abundant element in the Earth's crust, about as abundant as copper and more so than tin. Neodymium is more abundant than gold. The scarcest of the lanthanides, thulium, is more abundant than arsenic or mercury and they are not considered to be rare. The "rare" in rare earth elements originally referred to them typically being widely dispersed in very small quantities throughout the Earth's crust and very difficult to obtain in their pure form. Because lanthanides tend to congregate in the same minerals, the original isolation and identification of the lanthanides was very difficult and took well over a century of scientific development and discovery. It took over 100 years for all of the natrually occuring lanthanides to be discovered and over 150 years before the last lanthanide, the synthetic Promethium, would be "discovered".

The lanthanides are named after the element lanthanum (La) because it is the first in the group because it has the lowest atomic number, 57, of the group. The name "lanthanide" was introduced by Swiss born mineralogist Victor Moritz Goldschmidt (1888-1947) in 1925. Victor Goldschmidt, together with Russian mineralogist and geochemist Vladimir Vernadsky (1863-1945), were considered to be the founders of modern geochemistry and crystal chemistry. Goldschmidt was also the developer of the Goldschmidt Classification of elements. The name lanthanum comes from the Greek word λανθανω (lanthánein) meaning to lie hidden. This description may refer to the discovery of the element lanthanum as it was discovered "lying hidden" within a cerium bearing mineral that had previously been analysed. Many of the lanthanides were later discovered "lying hidden" within minerals that had previously been analysed.

The discovery of the lanthanides began in 1787 with the discovery of the mineral Ytterbite. Swedish chemist Carl Axel Arrhenius (1757-1824) found a dark mineral that he could not identify in a feldspar mine near Ytterby, on the island of Resarön, Sweden. Arrhenius named the black mineral Ytterbite after the nearby town of Ytterby. Arrhenius sent a sample of Ytterbite to Finish chemist Johan Gadolin (1760-1852) at Uppsala University, Finland, where he began a detailed analysis of it in 1794. He found it contained silica, alumina, iron oxide and an unknown "earth". Gadolin’s results were confirmed in 1797 by Swedish chemist Anders Gustaf Ekeberg (1767-1813). Ekeberg suggested the name yttria (later called yttrium) for the oxide of the new earth metal. Gadolin is credited with the discovery of the element yttrium. The mineral Ytterbite was renamed Gadolinite in 1800 by German chemist Martin Heinrich Klaproth (1743-1817) in honor of Johan Gadolin. Klaproth discovered uranium, zirconium and cerium.

Yttrium was the first of the rare earth elements to be discovered from Ytterbite. But the yttrium discovered by Gadolin also contained several other rare earth metal oxides. Over the next century, several of the remaining lanthanides were extracted from Ytterbite (Gadolinite). The Swedish chemist Carl Gustaf Mosander (1797-1858) was responsible for discovering lanthanum, erbium and terbium. The mineral Mosandrite was named in his honor in 1841.

The remaining lanthanide elements, ytterbium, thulium, holmium, dysprosium, lutetium and promethium, were discovered separately over many years. In 1907 lutetium was the last of the naturally occuring lanthanides to be discovered. However, the existence of an element between neodymium (atomic number 60) and samarium (atomic number 62) was predicted by Czech chemist Bohuslav Brauner (1855-1935) in 1902. This was confirmed by English phyisicist Henry Moseley (1887-1915) in 1914. Finally in 1945, after many attempts by many scientists, firm evidence that element 61 had been isolated was produced by Charles D. Coryell, Lawrence E. Glendenin, Jacob A. Marinsky, and Harold G. Richter at the Oak Ridge National Laboratory, Oak Ridge, Tennessee. They produced element 61 by fission of uranium and neutron bombardment of neodymium in a graphite reactor. They named the new element Promethium after the Greek Titan Prometheus, who, according to Greek mythology, stole fire from Mount Olympus to give to mankind. The name was accepted in 1949 by the International Union of Pure and Applied Chemistry (IUPAC). Promethium is considered a synthetic element and does not occur naturally in the Earth's crust. Promethium has been identified however, in the spectrum of the star HR465 in the Andromeda Galaxy approximately 780 kiloparsecs (2.5 million light-years; 2.4×1019 km) from Earth.

Listed below are gems containing at least one of the REE elements and the REE elements contained in each one.

 

Aeschynite

 

Allanite

 

Bastnaesite

 

Burbankite
Aeschynite-(Y)
(Y)

 

Allanite-(Ce)
(Ce)

 

Bastnaesite-(Ce)
(Ce)

 

Burbankite
(Ce)

 

 

 

 

 

 

 

Chevkinite-(Ce)

 

Eudialyte

 

Euxenite

 

Fergusonite
Chevnikite-(Ce)
(Ce)(La)

 

Eudialyte
(Ce)(Y)

 

Euxenite-(Y)
(Y)

 

Fergusonnite-(Ce)
(Ce)(La)(Y)

 

 

 

 

 

 

 

Gadolinite

 

Hibonite

 

Johnsenite-(Ce)
inclusion in Quartz

 

Kentbrooksite
Gadolinite-(Y)
(Y)
 

 

Hibonite
(Ce)(La)
 

 

Johnsenite-(Ce) (incl.)
(Ce)(Dy)(Gd)(La)
(Nd)(Pr)(Sm)(Y)

 

Kentbrooksite
(Ce)(La)(Nd)(Pr)(Sm)
 

 

 

 

 

 

 

 

Monazite

 

Mosandrite

 

Parisite

 

Remondite
Monazite
(Ce,La,Nd,Th)

 

Mosandrite
(Ce)

 

Parisite-(Nd)
(Ce)(La)(Nd)

 

Remondite-(Ce)
(Ce)(La)

 

 

 

 

 

 

 

Samarskite

 

Shomiokite

 

Synchysite-Y

 

Titanite
Samarskite-(Y)
 (Ce)(La)(Nd)(Pr)(Sm)(Y)

 

Shomiokite-(Y)
(Y)

 

Synchysite-(Y)
(Ce)(Y)

 

Titanite
 
(Ce)(La)(Nd)(Pr)(Sm)

 

 

 

 

 

 

 

Xenotime

 

Yttrocrasite

 

Yttrofluorite

 

Zircon
Xenotime-(Y)
(Dy)(Er)(Eu)(Gd)(Ho)(Lu)
(Nd)(Sm)(Tb)(Tm)(Y)(Yb)

 

Yttrocrasite-(Y)
(Y)
 

 

Yttrofluorite
(Y)
 

 

Zircon
(Ce)(La)(Nd)(Pr)(Sm)
 

 

More detailed information on the 15 lanthanides plus scandium and yttrium. Scandium and yttrium are not lanthanides, but are considered to be rare earth elements. They are listed in order of their atomic numbers.

Scandium (not a lanthanide, but considered a rare earth element)

atomic number:

21

atomic radius:

216 pm (Van der Waals)

atomic symbol:

Sc

standard state:

solid at 298 K (about 25°C)

atomic weight:

44.955912

melting point:

1541°C

electron configuration:

[Ar]4s23d1

boiling point:

2836°C

oxidation states:

3

color:

silvery white, yellowish tarnish

year discovered:

1879

discovered by:

Lars Fredrik Nilson (1840-1899)

Scandium was named from the Latin word Scandia, meaning Scandinavia.

  

Yttrium (not a lanthanide, but considered a rare earth element)

atomic number:

39

atomic radius:

219 pm (Van der Waals)

atomic symbol:

Y

standard state:

solid at 298 K (about 25°C)

atomic weight:

88.91

melting point:

1522°C

electron configuration:

[Kr]5s24d1

boiling point:

3345°C

oxidation states:

3

color:

silvery white, yellowish tarnish

year discovered:

1794

discovered by:

Johan Gadolin (1760-1852)

Yttrium was named after Ytterby, a town in Sweden near where the mineral Ytterbite (also named after Ytterby) was discovered in 1787 by Swedish chemist Carl Axel Arrhenius (1757-1824). Ytterbite was later renamed Gadolinite in honor of Johan Gadolin (1760-1852) who discovered the element yttrium from a Ytterbite sample.

  

Lanthanum

atomic number:

57

atomic radius:

240 pm (Van der Waals)

atomic symbol:

La

standard state:

solid at 298 K (about 25°C)

atomic weight:

138.9

melting point:

918 °C

electron configuration:

[Xe]6s25d1

boiling point:

3464 °C

oxidation states:

3

color:

silvery white

year discovered:

1839

discovered by:

Carl Gustaf Mosander (1797-1858)

Lanthanum was named from the Greek word lanthanein (λανθανω), meaning to escape notice.

  

Cerium

atomic number:

58

atomic radius:

235 pm (Van der Waals)

atomic symbol:

Ce

standard state:

solid at

atomic weight:

140.1

melting point:

798 °C

electron configuration:

[Xe]6s24f15d1

boiling point:

3443 °C

oxidation states:

4, 3

color:

silvery white

year discovered:

1801

discovered by:

Martin Heinrich Klaproth (1743-1817)

Cerium was named after the asteroid Ceres, which was discovered on January 1, 1801, two years before the discovery of cerium. Ceres was discovered and named by Italian astronomer Giuseppe Piazzi (1746-1826) after Ceres, the Roman goddess of agriculture. Ceres is the largest object in the asteroid belt which lies between the orbits of Mars and Jupiter. It was originally considered a planet, but was reclassified as an asteroid in the 1850s. It was designated as a dwarf planet by the International Astronomical Union (IAU) in 2006.

  

Praseodymium

atomic number:

59

atomic radius:

239 pm (Van der Waals)

atomic symbol:

Pr

standard state:

solid at 298 K (about 25°C)

atomic weight:

140.9

melting point:

931°C

electron configuration:

[Xe]6s24f3

boiling point:

3520°C

oxidation states:

3

color:

silvery white, yellowish tinge

year discovered:

1885

discovered by:

Carl Auer von Welsbach (1858-1929)

Praseodumium was named from the Greek words prasinos (πράσινος), meaning green, and didymos (δίδυμος), meaning twin. Praseodymium and neodymium are called "twins" because they are so much like lanthanum. Praseodymium is the "green" twin because when it becomes moist, it reacts with the oxygen in air to form praseodymium oxide which forms as a greenish-yellow scale (like rust) on its surface. To protect it from this reaction, it should be stored in mineral oil.

  

Neodymium

atomic number:

60

atomic radius:

229 pm (Van der Waals)

atomic symbol:

Nd

standard state:

solid at 298 K (about 25°C)

atomic weight:

144.242

melting point:

1021°C

electron configuration:

[Xe]6s24f4

boiling point:

3074°C

oxidation states:

3

color:

silvery white, yellowish tinge

year discovered:

1885

discovered by:

Carl Auer von Welsbach (1858-1929)

Neodumium was named from the Greek words neo (νέος) meaning new, and didymos (δίδυμος), meaning twin. Neodymium and praseodymium are called "twins" because they are so much like lanthanum.

  

Promethium

atomic number:

61

atomic radius:

236 pm (Van der Waals)

atomic symbol:

Pm

standard state:

solid at 298 K (about 25°C)

atomic weight:

145

melting point:

1042°C

electron configuration:

[Xe]6s24f5

boiling point:

~3000°C

oxidation states:

3, 2

color:

silvery white, yellowish tinge

year discovered:

1945

discovered by:

Charles D. Coryell, Jacob A. Marinsky, Lawrence E. Glendenin, Harold G. Richter

named by:

Grace Mary Coryell (1945)

Promethium was named after the Greek Titan Prometheus, who, according to Greek mythology, stole fire from Mount Olympus to give to mankind.

  

Samarium

atomic number:

62

atomic radius:

229 pm (Van der Waals)

atomic symbol:

Sm

standard state:

solid at 298 K (about 25°C)

atomic weight:

150.36

melting point:

1074°C

electron configuration:

[Xe]6s24f6

boiling point:

1794°C

oxidation states:

3, 2

color:

silvery white

year discovered:

1879

discovered by:

Paul Emile Lecoq de Boisbaudran (1838-1912)

Samarium was discovered in, and named for, the mineral Samarskite. Samarskite was named in honor of Colonel Vasilii Yevgrafovich Samarskii-Bykhovets (1803-1870), Chief of Staff of the Russian Corps of Mining Engineers.

  

Europium

atomic number:

63

atomic radius:

233 pm (Van der Waals)

atomic symbol:

Eu

standard state:

solid at 298 K (about 25°C)

atomic weight:

151.964

melting point:

1074°C

electron configuration:

[Xe]6s24f7

boiling point:

1794°C

oxidation states:

3, 2

color:

silvery white

year discovered:

1901

discovered by:

Eugène-Anatole Demarçay (1852-1903)

Europium was named after Europe.

  

Gadolinium

atomic number:

64

atomic radius:

237 pm (Van der Waals)

atomic symbol:

Gd

standard state:

solid at 298 K (about 25°C)

atomic weight:

157.25

melting point:

1313°C

electron configuration:

[Xe]6s24f75d1  

boiling point:

3273°C

oxidation states:

3

color:

silvery white

year discovered:

1880

discovered by:

Jean Charles Gallisard de Marignac (1817-1894)

Gadolinium was named after Finnish chemist Johan Gadolin (1760-1852). The mineral Ytterbite was renamed Gadolinite in 1800 also to honor him.

  

Terbium

atomic number:

65

atomic radius:

221 pm (Van der Waals)

atomic symbol:

Tb

standard state:

solid at 298 K (about 25°C)

atomic weight:

157.25

melting point:

1356°C

electron configuration:

[Xe]6s24f9

boiling point:

3230°C

oxidation states:

3

color:

silvery white

year discovered:

1843

discovered by:

Carl Gustaf Mosander (1797-1858)

Terbium was named after Ytterby, a town in Sweden near where the mineral Ytterbite (also named after Ytterby) was discovered in 1787 by Swedish chemist Carl Axel Arrhenius (1757-1824). Ytterbite was later renamed Gadolinite in honor of Johan Gadolin (1760-1852) who discovered the element yttrium from a Ytterbite sample.

  

Dysprosium

atomic number:

66

atomic radius:

229 pm (Van der Waals)

atomic symbol:

Dy

standard state:

solid at 298 K (about 25°C)

atomic weight:

162.5

melting point:

1413°C

electron configuration:

[Xe]6s24f10

boiling point:

2567°C

oxidation states:

3

color:

silvery white

year discovered:

1886

discovered by:

Paul Emile Lecoq de Boisbaudran (1838-1912)

Dysprosium was named from the Greek word dysprositos (δυσπρόσιτος), meaning hard to get.

  

Holmium

atomic number:

67

atomic radius:

216 pm (Van der Waals)

atomic symbol:

Ho

standard state:

solid at 298 K (about 25°C)

atomic weight:

164.93032

melting point:

1474°C

electron configuration:

[Xe]6s24f11

boiling point:

2700°C

oxidation states:

3

color:

silvery white

year discovered:

1878

discovered by:

Per Teodore Cleve (1840-1905)

Holmium was named from the Latin word Holmia meaning Stockholm, Sweden, Per Teodore Cleve's native city.

  

Erbium

atomic number:

68

atomic radius:

235 pm (Van der Waals)

atomic symbol:

Er

standard state:

solid at 298 K (about 25°C)

atomic weight:

167.259

melting point:

1529°C

electron configuration:

[Xe]6s24f12

boiling point:

2868°C

oxidation states:

3

color:

silvery white

year discovered:

1842

discovered by:

Carl Gustaf Mosander (1797-1858)

Erbium was named after Ytterby, a town in Sweden near where the mineral Ytterbite (also named after Ytterby) was discovered in 1787 by Swedish chemist Carl Axel Arrhenius (1757-1824). Ytterbite was later renamed Gadolinite in honor of Johan Gadolin (1760-1852) who discovered the element yttrium from a Ytterbite sample.

  

Thulium

atomic number:

69

atomic radius:

227 pm (Van der Waals)

atomic symbol:

Tm

standard state:

solid at 298 K (about 25°C)

atomic weight:

168.93421

melting point:

1545°C

electron configuration:

[Xe]6s24f13

boiling point:

1950°C

oxidation states:

3, 2

color:

silvery white

year discovered:

1879

discovered by:

Per Teodore Cleve (1840-1905)

Thulium was named after Thule, an ancient name for Scandinavia.

  

Ytterbium

atomic number:

70

atomic radius:

242 pm (Van der Waals)

atomic symbol:

Yb

standard state:

solid at 298 K (about 25°C)

atomic weight:

173.054

melting point:

819°C

electron configuration:

[Xe]6s24f14

boiling point:

1196°C

oxidation states:

3, 2

color:

silvery white

year discovered:

1878

discovered by:

Jean Charles Galissard de Marignac (1817-1894)

Ytterbium was named after Ytterby, a town in Sweden near where the mineral Ytterbite (also named after Ytterby) was discovered in 1787 by Swedish chemist Carl Axel Arrhenius (1757-1824). Ytterbite was later renamed Gadolinite in honor of Johan Gadolin (1760-1852) who discovered the element yttrium from a Ytterbite sample.

  

Lutetium

atomic number:

71

atomic radius:

221 pm (Van der Waals)

atomic symbol:

Lu

standard state:

solid at 298 K (about 25°C)

atomic weight:

174.9668

melting point:

1663°C

electron configuration:

[Xe]6s24f145d1

boiling point:

3402°C

oxidation states:

3

color:

silvery white

year discovered:

1907

discovered by:

Georges Urbain (1872-1938) and
Carl Auer von Welsbach (1858-1929)

Lutetium was named after Lutetia, an ancient Latin name for Paris.

 

 


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