His chemistry research emphasized the study of minerals, especially the newly-discovered rare earths, having devised means of separating yttrium and erbium.

[3] Berlin graduated from the University of Uppsala with a doctor of philosophy in 1833, having studied under the tutelage of Jöns Jacob Berzelius.

[3] Berlin published two popular textbooks, which emphasized description and practical knowledge over theory (of which there was relatively little at the time).

[3] The third edition of Berlin's textbook, which appeared in 1870, was heavily revised by Christian Wilhelm Blomstrand, who added his own systematization of the elements.

[3] In 1787 Carl Axel Arrhenius found a dark mineral in a feldspar mine in the village of Ytterby, Sweden.

A number of researchers tried to identify elements composing the ore, which were particularly hard to separate due to their similar chemical properties.

[12] The naming of ytteria's components became further complicated in 1862, when Marc Delafontaine reported its separation into yttrium and a yellow peroxide, which he first called mosandrum (after Mosander) and later terbium.