Least useful stable element?

[Nereid]

An idle curiosity ...

Elements such as H, C, O, and N are exceedingly useful, not only because our lives depend upon them, but also because they - and compounds made from them - have (collectively) very high commercial value.

Ditto for Fe, Ca, Mg, and many other elements.

So what's the least useful stable element*?

It should not be necessary for life - there are quite a lot of elements which are necessary, albeit in only trace amounts (e.g. Cd, I, V) - but should have minimal commercial value (so elements such as Pb, Rb, and Ag don't qualify).

My guess would be one of the rare earth elements (some definitely do not qualify, e.g. Sm), or Sc, Y, Lu, or Hf.

* let's include Bi here, even though, technically, it's not stable

[Swift]

I assume from how you've framed the question, that you mean least useful for biochemistry. The rare earth elements are certainly useful for other things - LINK

Rare earth elements are incorporated into many modern technological devices, including superconductors, samarium-cobalt and neodymium-iron-boron high-flux rare-earth magnets, electronic polishers, refining catalysts and hybrid car components (primarily batteries and magnets).[5] Rare earth ions are used as the active ions in luminescent materials used in optoelectronics applications, most notably the Nd:YAG laser. Erbium-doped fiber amplifiers are significant devices in optical-fiber communication systems. Phosphors with rare earth dopants are also widely used in cathode ray tube technology such as television sets. The earliest color television CRTs had a poor-quality red; europium as a phosphor dopant made good red phosphors possible. Yttrium iron garnet (YIG) spheres have been useful as tunable microwave resonators. Rare earth oxides are mixed with tungsten to improve its high temperature properties for welding, replacing thorium, which was mildly hazardous to work with.

[grant hutchison]

John Emsley's Nature's Building Blocks discusses the usefulness of every element in the periodic table.
For lutetium, he reports that world production is around 10 tonnes per year, "but little use is made of it". Neutron-irradiated lutetium has been used as a pure beta-emitter in the oil industry, and "a tiny amount" is used as a dopant for gadolinium-gallium garnet bubble memories.

But I haven't sat down and browsed through the "economic" entry for every element.

Grant Hutchison

[Nereid]

I assume from how you've framed the question, that you mean least useful for biochemistry. The rare earth elements are certainly useful for other things - LINK

Actually I meant generally.

I know that some of the rare-earths are very important (Sm, Nd, Eu, Yb, Er), but am not sure that they all are. From your link, Y is no longer in the running (I hadn't appreciated that it, along with Lu and Sc, are, strictly speaking, rare-earth elements; I thought 'rare-earths' and lanthanides were synonyms).

[Swift]

Like a parent feels about their children, as an Inorganic Chemist, I love all my elements equally.

[grant hutchison]

Like a parent feels about their children, as an Inorganic Chemist, I love all my elements equally.

But don't you ever suffer from Carbon Envy?

Grant Hutchison

[George]

But don't you ever suffer from Carbon Envy?

It may be the life of the party but there are loners that are far more noble.

[Jeff Root]

Cadmium and vanadium are required by living things??? Humans?

-- Jeff, in Minneapolis

[grant hutchison]

Cadmium and vanadium are required by living things??? Humans?

Vanadium: for sure in some algae, probably in humans. Cadmium, not so much. In humans it steals into the body through the zinc-handling system, and can be harmful. I wonder if Nereid was thinking of chromium, instead.

Grant Hutchison

[AndreasJ]

According to this abstract, trace amounts of vanadium are needed for normal growth in rats. Rats and people being, in the grand scheme of things, much the same, one might suspect the same applies to humans. It doesn't say, however, just what the vanadium does.

The WP pages also list a few other biological rôles for V, and one for Cd; as a zinc replacement in certain diatoms.

[grant hutchison]

We know vanadium alters the activity of various cellular enzyme systems in vitro, and we know we can induce a deficiency syndrome in lab mammals. There's just never been a deficiency syndrome described in humans, because vanadium is rather ubiquitous in food in trace amounts. To answer the question "Is vanadium an essential trace element in humans?" categorically, we'd really need to see people develop some sort of syndrome when deprived of vanadium while being otherwise well-nourished, and then recover from that syndrome when provided with vanadium in an otherwise unaltered diet. Hence my less-than-categorical answer.

Grant Hutchison

[Jeff Root]

I thought it might be chromium, too. I knew that cadmium is toxic,
though how toxic, I don't know, and I thought it might be required
despite being toxic!

I got lucky and pulled the right yearbook (1973) off the shelf on the
first try, and opened it just one page away from the article that I
remembered and the photo that I remembered and had previously
(a couple of years ago) gone looking for in a different set of books,
having forgotten that it was in the yearbook. So I've finally found
the photo again.

It is an article on trace elements in human nutrition. Vanadium is
marked as "essential trace element proven only in animals". The
photo is of a teaspoon containing a small amount of chromium,
"the lifetime supply needed by the average person."

-- Jeff, in Minneapolis

[Swift]

Chemical & Engineering News just had an article about Metalloproteins (proteins contains a metallic element) (July 26, 2010, Volume 88, Number 30, p. 7 - sorry electronic content for members only). Apparently, figuring out the metal involved is not as routine as one might imagine.

Metalloproteins may be more numerous and diverse than previously suspected, researchers report (Nature, DOI: 10.1038/
nature09265).

Proteins often use metals as cofactors and catalysts, but predicting which proteins incorporate which metals is difficult because of the variety of metal-binding sites found in proteins.

“There is no routine method to analyze a complement of metalloproteins,” says Nigel J. Robinson of Newcastle University, in England, who was not involved with this study. “The challenge is an important one because nearly half of the structurally characterized enzymes in the Protein Data Bank need metals, yet it is not possible to predict with certainty which proteins will use which metals.”

Indeed, most metals associated with proteins are discovered “after the fact” as people study particular proteins, says study leader Michael W. W. Adams of the University of Georgia, Athens. “We used the reverse approach,” he says. “Rather than purifying proteins and seeing what metals they contain, we purified metal peaks and then tried to see what proteins were associated with the metal.”

In their study, they looked at the microorganism Pyrococcus furiosus. Five metals involved with proteins were already known: Fe, Co, Ni, W, Zn; and they discovered three new ones: V, Mn, Mo. And that's just one organism.

[Nick Theodorakis]

Chemical & Engineering News just had an article about Metalloproteins (proteins contains a metallic element) (July 26, 2010, Volume 88, Number 30, p. 7 - sorry electronic content for members only). Apparently, figuring out the metal involved is not as routine as one might imagine.

In their study, they looked at the microorganism Pyrococcus furiosus. Five metals involved with proteins were already known: Fe, Co, Ni, W, Zn; and they discovered three new ones: V, Mn, Mo. And that's just one organism.

Three new what? Do you mean three new metalloproteins, or three metals not previously described as protein cofactors? Manganese and molybdenum have already been described as being cofactors for some enzymes (at least one form of superoxide dismutase uses Mn, and several phosphatases do, and Mo is a cofactor for nitrogenase, the enzyme that "fixes" atmospheric nitrogen).

Nick

[Swift]

Three new what? Do you mean three new metalloproteins, or three metals not previously described as protein cofactors? Manganese and molybdenum have already been described as being cofactors for some enzymes (at least one form of superoxide dismutase uses Mn, and several phosphatases do, and Mo is a cofactor for nitrogenase, the enzyme that "fixes" atmospheric nitrogen).

Nick

Sorry if that I was unclear (I was trying not to overdue the copyright infringement). Three new metals not previously described as protein cofactors for this particular organism. I think the main point was to demonstrate their technique, which has the potential to really expand the number of metals found in metalloproteins. I think the quote from Nigel J. Robinson in what I quoted is particularly interesting (and was news to me).

[Nereid]

A few years ago I started to get interested in microbiology, especially in bacteria and archaea. It's a totally different world!

"necessary for life" - it's one thing for an element to be essential for our lives, as Homo sapiens organisms. But our lives depend, critically, on things like the thousands of symbiotic bacterial species, in our guts, for example. And there are the other bacteria which are necessary for the lives of what we eat, animals and plants. And the other bacteria in the ecosystems upon which we depend - perhaps not as extremely as 'necessary'.

What elements are necessary for all those bacteria? I'd say no one really knows the full extent yet ...

Dietary mineral^WP gives an interesting summary; I doubt that it's entirely accurate, or up to date however. For example, S is certainly essential for life, as is Co, even though we (Homo saps) get what we need from what's in the food we eat. Note this comment: "Arsenic, boron, bromine, cadmium, silicon, tungsten, and vanadium have established, albeit specialized, biochemical roles as structural or functional cofactors in other organisms." I.e. they are essential for at least some forms of life.

(I recall reading an article, many years ago now, on how Sn had been discovered to be essential for at least some animal species; it's not in the WP list).

Some bacteria (and, no doubt, archaea) can live with what is to us highly toxic elements, for example Hg; whether such elements are essential for those bacteria - as opposed to the bacteria merely exploiting an unusual metabolic pathway, as one of several available to them - I do not know.

[Nereid]

Right now, I think the least useful stable element is either Lu or Hf, although there are quite a few that seem to have only one or two specialised uses, with very narrow impact, e.g. Sc.

[HenrikOlsen]

Hf is used in arch welding and plasma cutting electrodes as well as nuclear control rods and for specialized alloys.
Hafnium oxide is used in sub-45nm semiconductors as well.
Definitely not useless and though it is highly specialized applications, it's at least 4 in very different fields.

[Swift]

Hf is used in arch welding and plasma cutting electrodes as well as nuclear control rods and for specialized alloys.
Hafnium oxide is used in sub-45nm semiconductors as well.
Definitely not useless and though it is highly specialized applications, it's at least 4 in very different fields.

Hf has very similar chemistry to Zr and is found in a lot of zirconia ceramics. In many cases, the Hf concentration can have significant effects on the properties of those ceramics, both good and bad. I suspect the same is true for zirconium metallurgy, but I have no personal experience.

[Ivan Viehoff]

Right now, I think the least useful stable element is either Lu or Hf, although there are quite a few that seem to have only one or two specialised uses, with very narrow impact, e.g. Sc.

I think we should reckon this by quantity of production, and value of that production.

For example, Lutetium is about $10/g (for the oxide) and its production (of the oxide) is 10 tonnes, so that is around $100m worth of annual production.
Much less Osmium is produced, only 1 tonne. But it is a lot more expensive, $70/g. So $70m annual production, I would say it less useful than Lutetium, though fairly close to this level of approximation.
There are 3 tonnes of Irridium, so at a similar price to Osmium, that is clearly rather more useful.
Hafnium production is about 50 tonnes. Price is around $1200/kg, so that is $60m worth of annual production. Moderately less useful than Osmium, but hard to tell at this level of approximation.

But Scandium clearly wins hands down. Annual production about 2 tonnes, at price of only around $600/kg, that's only $1.2m worth of annual production. The least useful element by a long calcium carbonate.

I used a variety of sources for these data that Google found me. I also considered Rhenium, Rhodium, Ruthenium and Tellurium. www.3rd1000.com is a nice data source for elements.

[jj_0001]

How about thallium. Other than uses for radioactive thallium to test heart function, what good is it, other than to be really bad for any known organism?

[Ivan Viehoff]

You'll find quite a few of uses of Thallium on the wikipedia page. I never even thought of looking up details for thallium, because I am aware of its usefulness in synthesizing organic chemicals. Though I think because of its considerable toxicity this is avoided these days unless the alternatives are terrible. But in fact not much of it is produced, and the price isn't very high. Production is about 10 tonnes, down from about 15 tonnes a few years ago. It was about $4,500 per kg a couple of years ago, which is actually quite a large increase in price on the previous decade. So total production worth about $45m. Good spot, at the moment that makes it less useful than anything other than Scandium by the above methodology.

[Nereid]

I think we should reckon this by quantity of production, and value of that production.

For example, Lutetium is about $10/g (for the oxide) and its production (of the oxide) is 10 tonnes, so that is around $100m worth of annual production.
Much less Osmium is produced, only 1 tonne. But it is a lot more expensive, $70/g. So $70m annual production, I would say it less useful than Lutetium, though fairly close to this level of approximation.
There are 3 tonnes of Irridium, so at a similar price to Osmium, that is clearly rather more useful.
Hafnium production is about 50 tonnes. Price is around $1200/kg, so that is $60m worth of annual production. Moderately less useful than Osmium, but hard to tell at this level of approximation.

But Scandium clearly wins hands down. Annual production about 2 tonnes, at price of only around $600/kg, that's only $1.2m worth of annual production. The least useful element by a long calcium carbonate.

I used a variety of sources for these data that Google found me. I also considered Rhenium, Rhodium, Ruthenium and Tellurium. www.3rd1000.com is a nice data source for elements.

Very good, a way to quantitatively assess 'least useful'!

In addition to the total commercial value - I agree that quantity alone is quite unreliable - I think the number of distinct applications is important. In that regard is there much to choose between Lu, Sc, Hf, Ir, and Os? My guess would be that Ir and Os have more, with Lu and Sc having the fewest.

Initially I too thought that Re would likely be in the running, based on its scarcity, but a quick google set me straight! Ru, Rh, and Te were never in the running IMHO; the first two are quite useful, metallurgically speaking, and Te is jolly useful in semiconductors (though I didn't know of its metallurgical uses until I googled).

[Nereid]

How about thallium. Other than uses for radioactive thallium to test heart function, what good is it, other than to be really bad for any known organism?

There are rather a lot of uses of Tl, though not all are, um, attractive (rat poison!? Now banned everywhere, AFAIK): it does have medical uses apart from cardio stress testing, also in optics and electronics, and more. That makes it more useful than Sc, Hf, and Lu, even though its total commercial value (production x price) suggests otherwise.

[Ilya]

In SF parody Illegal Aliens by Nick Polotta, thulium is the most useless element in the universe, which is why Galactic Empire (or whatever it is called in the book) makes currency out of it. Nobody in their right mind will melt down thulium coins because they have no other value.

So I checked... and it may true!

Thulium has very few commercial uses. Radioactive thulium can be utilized as a power source for portable x-ray machines and is produced by irradiating the element in a nuclear reactor. Thulium may also be utilized to make magnetic ceramic materials found in microwave equipment.

IOW, stable isotopes of thulium (which OP specified) really are nearly-useless.

[Ivan Viehoff]

IOW, stable isotopes of thulium (which OP specified) really are nearly-useless.

That's a bit like saying that iron oxide is near-useless stuff. Nevertheless enormous quantities of it are mined. Thulium's very expensive stuff, but it must be good stuff, because on a price x quantity test it's some way down the list.

[Ivan Viehoff]

In addition to the total commercial value - I agree that quantity alone is quite unreliable - I think the number of distinct applications is important. In that regard is there much to choose between Lu, Sc, Hf, Ir, and Os? My guess would be that Ir and Os have more, with Lu and Sc having the fewest.

So what are $70m dollars worth of Lutetium oxide used for, if its uses are so insignificant? I wonder if that is explained by this sentence in Wikipedia "stable lutetium can be used as catalysts in petroleum cracking in refineries and can also be used in alkylation, hydrogenation, and polymerization applications" which sounds like quite an important and diverse rance of uses in organic synthesis, covers the issue.

[Ivan Viehoff]

So what are $70m dollars worth of Lutetium oxide used for, if its uses are so insignificant? I wonder if that is explained by this sentence in Wikipedia "stable lutetium can be used as catalysts in petroleum cracking in refineries and can also be used in alkylation, hydrogenation, and polymerization applications" which sounds like quite an important and diverse rance of uses in organic synthesis, covers the issue.

I just had a bad feeling about this, and have done a bit more googling. I misread the source in supposing that the $10/g price is for Lutetium oxide, it is for the metal, but very little Lutetium is used as metal as it is so difficult to extract. I've just seen a price of about $686 for a 1kg pack of Lutetium oxide, including shipping from China. So actually we are talking about more like $6m worth of production. Getting closer to Scandium levels of usefulness.

[xylophobe]

There are rather a lot of uses of Th, though not all are, um, attractive (rat poison!? Now banned everywhere, AFAIK): it does have medical uses apart from cardio stress testing, also in optics and electronics, and more. That makes it more useful than Sc, Hf, and Lu, even though its total commercial value (production x price) suggests otherwise.

"Th" stands for thorium
"Tl" stands for thallium

Periodic Table of Elements

[Nereid]

"Th" stands for thorium
"Tl" stands for thallium

Periodic Table of Elements

Thanks xylophobe!

Of course I knew that, really, honestly, ... it was just a typo m'lord ...