Erbium confusions

Yttrium (j Y) is often confused with another element of the lanthanide series of rare Earths— Ytterbium ( Yb). Also confusing is the fact that the rare-earth elements terbium and erbium were found in the same minerals in the same quarry in Sweden. Yttrium ranks second in abundance of all 16 rare-earth, and Ytterbium ranks 10th. Yttrium is a dark silvery-gray hghtweight metal that, in the form of powder or shavings, will ignite spontaneously. Therefore, it is considered a moderately active rare-earth metal. 

Carl Gustaf Mosander, a Swedish chemist, successfully separated two rare-earths from a sample of lanthanum found in the mineral gadolinite. He then tried the same procedure with the rare-earth yttria. He was successful in separating this rare-earth into three separate rare-earths with similar names yttia, erbia, and terbia. For the next 50 years scientists confused these three elements because of their similar names and very similar chemical and physical properties. Erbia and terbia were switched around, and for some time the two rare-earths were mixed up. The confusion was settled ostensibly in 1877 when the chemistry profession had the final say in the matter. However, they also got it wrong. What we know today as erbium was originally terbium, and terbium was erbium. 

The names of the elements erbium and terbium were confused in the 19th century. Delafontaine used spectral analysis to prove the existence of erbium and terbium, but in his publications (probably unintentionally), he interchanged the... 

Erbium — Ytterby, a town in Sweden), Er at. wt. 167.26(3) at. no. 68 m.p. 1529°C b.p. 2868°C sp. gr. 9.066 (25°C) valence 3, Erbium, one of the so-called rare-earth elements of the lanthanide series, is found in the minerals mentioned under dysprosium above. In 1842 Mosander separated yttria, found in the mineral gadolinite, into three fractions which he called yttria, erbia, and terbia. The names erbia and terbia became confused in this early period. After 1860, Mosander s terbia was known as erbia, and after 1877, the earlier known erbia... 

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