Talk:Rare earth element/Archive 1

Archive 1

Promethium

The article was saying promethium "is not generally not considered a rare earth element." Since Promethium is man-made, I'm guessing it's NOT a rare-earth element, so I fixed it this way. If that is incorrect, please fix it. - TheMaster42 20:37, 18 January 2006 (UTC)

That's correct. Thanks for catching and fixing it. --Karnesky 23:13, 18 January 2006 (UTC)

Where is the reference for Promethium not being a rare earth? It is considered a rare earth element in webelements: [[1]], in Brittanica [[2]] and just about every other webpage found by conducting a google search. Don't be confused by the term rare earth, considering these elements are far more abundant than many other elements. So since they are not rare, neither do they have to be from the earth. The key is the term rare earth is just a common term for lanthanoid and as such Promethium is a rare earth. Polyamorph (talk) 20:36, 16 December 2007 (UTC)

There are many definitions of what does and does not constitute a REE. Some of these definitions include the terms "naturally occurring" [such as the one in the OED (although, in notes that one notable use was "1959 Nomencl. Inorg. Chem. (I.U.P.A.C.) 6 The name rare-earth metals may be used for the elements Sc, Y, and La to Lu inclusive. 1965.")] --Karnesky (talk) 21:18, 16 December 2007 (UTC)

If there are many definitions then for the article to maintain neutrality neither definition should be quoted without mentioning the other. The current bias expressed in this article is clearly disputable and clarification should be made Polyamorph (talk) 21:46, 16 December 2007 (UTC)

Quoting Itub (in the lanthanide article talk page) "That's right, even the IUPAC guidelines apply the term rare earths to "Sc, Y, and the lanthanoids" (and the lanthanoids explicitly include Pm)". This article is clearly innaccurate and should be altered to clarify the definition. Polyamorph (talk) 13:09, 17 December 2007 (UTC)

I have removed the uncited statements which describe Promethium as not being a rare earth. A sentence should be incorporated at some point (with citation(s)) which states in some definitions Promethium is not considered a rare earth since it is not naturally occuring. Polyamorph (talk) 13:16, 17 December 2007 (UTC)

I finished what you started by updating the count to 17, and removing the statements that IUPAC deprecates the name, as the 2004 Nomenclature of Inorganic Chemistry explicitly calls the name "IUPAC-approved" and I haven't seen any IUPAC source saying the opposite. IMO, using the Oxford English Dictionary as an authority for chemical nomenclature does not make much sense. --Itub (talk) 15:47, 17 December 2007 (UTC)

It makes much more sense now, I must be tired since I missed changing the element count but thanks for your help. Polyamorph (talk) 16:15, 17 December 2007 (UTC)

well I never, "rare earth" makes it into IUPAC's red book! Is nothing sacred any more? lol --feline1 (talk) 17:40, 17 December 2007 (UTC)

today's no-nonsene edits

OK, I have been a bit ruthless with this article today. My rational is that "rare earth elements" is a deprecated trivial name for "lanthanides". All the proper discussion of these elements should be over at lanthanides. The other info that really needs to be in this rare earth page is why the trivial name arose, and why it's no longer favoured. I believe this is fairly well covered as it stands now.--feline1 22:36, 7 December 2005 (UTC)

In addition to the 'earth'->'oxide' connection, we really should say a bit more about why the trivial names arose. 1)They were, at one time, thought to be non-abundant 2)the reasons which make them much more expensive than the more abundant neighbors: a)they oxidize easily, b)they occur widely in low concentrations, rather than in high concentration regions (ore veins), and c)they are difficult to separate. -- Karnesky

Edits look good! -- Karnesky 00:36, 8 December 2005 (UTC)

I like the info on this page. I would also like to see the prices of these elements and get a sense of which elements are in greatest demand by volume. WpZurp 12:12, 27 July 2005 (UTC)

Number

I may be mistaken, but it appears that if the list includes thirteen of the fourteen lanthanides and two other metals, there are fifteen rather than sixteen rare earth metals. Correct me if I'm wrong. Chachilongbow 18:28, 13 July 2006 (UTC)

Ok, reading lanthanides cleared that up for me. I'm going to change the wording to make it more clear. Chachilongbow 18:30, 13 July 2006 (UTC)

Rare earth or Rare earth element?

The Rare earth article was becoming very much like Rare earth element, discussing what classifies as a rare earth element etc. I think anything regarding the metallic elements should be on the latter, and the former should be restricted to the oxides.

So I've merged most of the content from Rare earth into here. I tried to get any extra information in, but there was very little (if any) that wasn't filler or contradictory. I've put the things I couldn't merge in here in case anyone who Really knows what they're doing wants to put them back.

Wikipedia's very own periodic table includes actinides as rare earth elements, as do several other sources. But some use rare earth metal as a direct synonym for lanthanide, sometimes including yttrium and scandium, like the article in its current state. I'm sure the confusion is for technical or historical reasons I can't fathom. Also, if actinides are included then some of the chemical information lower in the article becomes invalid, as it applies to lanthanides, and probably should be moved there anyway.

Sometimes the radioactive actinides are included, so that all elements in the f-block are considered "rare earth metals" in a manner similar to how d-block elements are called "transition metals". The actinides are ...[big long list of actinides]. All are radioactive, and only thorium and uranium are found in large amounts in nature because of their very slow decay rate; one might argue that the elements from neptunium on cannot be properly called "rare earths" because they are all artificial.

The second part is about market values. This might fit in the paragraph "The principle economic sources...". I feel quite bad about deleting this, as it apparently in response to a request, but it's not very specific and difficult to fit in the article without more qualification.

The cheapest rare earth metals are yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, and gadolinium, along with thorium and uranium; while the most expensive are scandium, europium, thulium, and lutetium.

I also shuffled the paragraphs around a bit so it now goes, roughly:

• definition
• terminology
• characteristics
• applications
• some other stuff

I know this leaves practically nothing at Rare earth again, but maybe there is an article in the oxides - some examples, history of discovery, ores, terminology, applications (if any), and stuff :) It seems like alkaline earth is having similar trouble as an article.

Of course, if an article can never be made out of Rare earth, I suggest the disambig page at Rare Earth be merged into it [3].

Moogsi 08:28, 9 September 2005 (UTC)

Most rare?

So which is the most rare?

As in the article, they are all relatively abundant (but expensive to mine and extract). The most expensive is scandium. --Karnesky 20:38, 28 May 2006 (UTC)

Rare at all?

There's a contradiction between this article and the current article for lutetium. This article says that lutetium is 200 times more abundant than gold; the lutetium article says it "is the least abundant of all naturally occurring elements." Could someone clarify and update both articles? Thanks. Jeneralist 17:33, 17 September 2006 (UTC)

I'm afraid the lutecium article is talking bollocks! --feline1 17:52, 17 September 2006 (UTC)

Rare earths are not rare. But their high degree of electron affinity results in them being poorly separable from rocks and hence it is difficult to find rare earth ore deposits. This situation is enhanced for heavy ree's which have an even higher charge/radius ratio (IP); they almost always stay in melts rather than migrate upwards into ore deposits

F-block

Does rare earth elements means the f-block. Cosmium 02:07, 18 February 2007 (UTC)

As per the article, most of the lanthanides (which, with the actinides, make up half of the f-block) are considered to be REEs & most REEs are lanthanides. However, "rare earth" is NOT synonymous with "f-block." --Karnesky 05:10, 18 February 2007 (UTC)

"The former two are included as they tend to occur with the latter..."

What former two and latter is the second intro sentence supposed to be referring to? Could someone who can figure that out please edit it so it's clearer? Thanks. 75.18.200.11 02:34, 13 May 2007 (UTC)

Fixed this statement Polyamorph (talk) 10:26, 19 April 2008 (UTC)

Archive 1