 Discovery Information
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| Who: Robert Bunsen, Gustav Kirchoff |
| When: 1861 |
| Where: Germany |
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| Name Origin
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| Latin: rubidus (red); the colour its salts impart to flames. |
| "Rubidium" in different languages. |
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| Sources
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| Occurs abundantly, but so widespread that production is limited. Usually obtained from lithium production. Occurs in the minerals leucite, pollucite ((Cs,Na)2Al2Si4O12.2H2O) and zinnwaldite (KLiFeAl(AlSi3)O10(OH,F)2).
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| Abundance
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| Universe: 0.01 ppm (by weight) |
| Sun: 0.03 ppm (by weight) |
| Carbonaceous meteorite: 3.3 ppm |
| Earth's Crust: 60 ppm |
| Seawater: 0.12 ppm |
| Human: |
| 4600 ppb by weight |
| 340 ppb by atoms |
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| Uses
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| Used in fireworks (to give them a purple colour), atomic clocks, photoelectric cells, vacuum tubes, heart research and as
a catalyst.
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| History
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| Rubidium was discovered in 1861 by Robert Bunsen and Gustav Kirchhoff in the mineral lepidolite ((KLi2Al(Al,Si)3O10(F,OH)2) through the use of a spectroscope. However, this element had minimal industrial use until the 1920s. Historically, the most
important use for rubidium has been in research and development, primarily in chemical and electronic applications.
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| Notes
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| Rb has been used extensively in dating rocks; 87Rb decays to stable 87Sr by emission of a negative beta particle. During fractional crystallization, Sr tends to become concentrated in plagioclase,
leaving Rb in the liquid phase. Hence, the Rb/Sr ratio in residual magma may increase over time, resulting in rocks with increasing
Rb/Sr ratios with increasing differentiation. Highest ratios (10 or higher) occur in pegmatites. If the initial amount of
Sr is known or can be extrapolated, the age can be determined by measurement of the Rb and Sr concentrations and the 87Sr/86Sr ratio. The dates indicate the true age of the minerals only if the rocks have not been subsequently altered.
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| Hazards
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| Rubidium reacts violently with water and can cause fires. |
