didymium

American  

[dahy-dim-ee-uhm, dih-] / daɪˈdɪm i əm, dɪ- /

noun

Chemistry.

1. a mixture of neodymium and praseodymium, formerly thought to be an element. Di

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didymium British  

/ daɪˈdɪmɪəm, dɪ- /

noun

1. a mixture of the metallic rare earths neodymium and praseodymium, once thought to be an element

2. a mixture of rare earths and their oxides used in colouring glass

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Etymology

Origin of didymium

< New Latin < Greek dídym ( os ) twin ( didymous ) + -ium; so named by Swedish chemist Carl Mosander (1797–1858), who discovered it in 1843, from its close association with lanthanum

Example Sentences

The separation of lanthanum and didymium in the solution from which the cerium has been precipitated is effected by precipitating them together as oxalates, igniting, and dissolving in dilute nitric acid.

From A Text-book of Assaying: For the Use of Those Connected with Mines. by Beringer, Cornelius

A subnitrate of didymium is formed, and remains as an insoluble residue on extracting with hot water.

From A Text-book of Assaying: For the Use of Those Connected with Mines. by Beringer, Cornelius

On treating with oxalic acid, cerium, lanthanum, and didymium are precipitated as oxalates, which on ignition are converted into oxides.

From A Text-book of Assaying: For the Use of Those Connected with Mines. by Beringer, Cornelius

This looks like a didymium and in so far justifies the opinion of earlier students.

From The North American Slime-Moulds A Descriptive List of All Species of Myxomycetes Hitherto Reported from the Continent of North America, with Notes on Some Extra-Limital Species by MacBride, Thomas H. (Thomas Huston)

It occurs in certain rare minerals, as cerite, gadolinite, orthite, etc., and was so named from the difficulty of separating it from cerium, didymium, and other rare elements with which it is usually associated.

From The Gutenberg Webster's Unabridged Dictionary Section I, J, K, and L by Project Gutenberg