Talk:Olivine

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IMHO your page on olivine basalts is simply too bloody awful to be edited. The alleged pix of olivine seeme to be small fragments of basalt and no olivine is visible. "Small amounts of olivine" may be visible on Mars but from meteorite samples we know that some types of surface rocks have 60% olivine (it also forms large but variable amounts in chondrite meteorites depending in the oxidation state). Olivine does not occur in norites, here the dominant mineral is a quartz saturated orthopyroxene. Olivine-rich rocks mainly from the Archaean are the source of multi-billion dollar nickel mining industry. As the whole of the Earths mantle is composed of more than 80% olivine or its high pressure equivilent, it is the most common mineral knowns. Without olivine and its structural and chemical stability there would no no Earth.
I wish I could help, but it would be a protracted job.
(Dr) B. Gunn infor@geokem.com

You are right - it is badly in need of a re-write. It is on my long to do list... someday. -Vsmith 04:24, 1 Nov 2004 (UTC)

I am attempting a first edit now.. - andreww 19:20, 21 Nov 2004 (GMT)

Ok I have started to sort this page out (though it is in no way finished). I removed the following bits because they seem to be wrong:

Olivine crystallizes in the orthorhombic system in somewhat flattened forms 
but may occur massive or granular.

As this is is mixing the crystal system (orthorombic) and its habit - and I could not work out where it should go.

of magnesia

I don't think a link to periclase is very helpful - magnesium insted maybe?

Traces of olivine were observed by the Mars Odyssey orbiter on the surface of Mars, 
suggesting the  possibility of liquid water in the past.

I don't follow the argument that olivine sugests water. In general olivine + water --> serpentine - what is the source for this statment? From memory the water evidance was the identification of jarrosite (some kind of clay mineral).

I intend to add to the crystal structure bit (and add a diagram or two) and add an additional section on the high pressure polymorphs (wadslyeite and ringwoodite) and phase diagram but if somebody else could clear up the basic geology (and economic geology?) that would save me geting it wrong. And I dont have any good pictures of olivine I can upload so that would be a big help! - andreww 19:20, 21 Nov 2004 (GMT)

Great! You got to it before me :-) I tweaked a bit and got rid of magnesia (1911 terminology). Added my refs. -Vsmith 01:27, 22 Nov 2004 (UTC)

New image

I may be wrong but is the new image of olivine not a peridotite xenolith (with green olivine and black pyroxene) in basalt? If it is it would make a good illustration for the article on the mantle and on pyroxen (with a sutible caption). Andreww 07:46, 30 July 2005 (UTC)

I agree with you - as I understand the San Carlos peridot inclusions are likely xenoliths. Use where it fits. I just aquired the sample and was experimenting with a new camera - could be a bit sharper methinks. Need a scale also, the image is about 4-5 cm across. I may re-take the photo and replace with a better image -- someday. Vsmith 13:53, 30 July 2005 (UTC)

Whenever I read "olivine" I think of the image of the cute, translucent, green gemstone at the top of the introduction. But, most of the text about it is talking about a mineral in an opaque rock. Surely, the upper mantle is not composed of translucent green gemstone. Couldn't we have a picture of more rugged, typical Olivine rock? Something that a normal person might find. The gemstone image is nice, but that could slide further down the page. OsamaBinLogin (talk) 18:34, 27 March 2024 (UTC)

Gadget Referrence

Sorry, I'm new at this, please correct this if I input incorrectly. I haven't registered/tutorialed yet.

Anyway, in a game, "Gadget: Past as Future," Olivine is used as a power-source for a subterranean transport. Pretty out-there, but I thought it was worth a mention. ...Olivine is used in furnace bricks, I've read, but is there really anything reactant about the stuff? -TJ —The preceding unsigned comment was added by 76.177.199.23 (talk) 04:33, 6 December 2006 (UTC).

Interesting tidbit of "Popular Culture!" Unfortunately olivine does not contain much of anything reactive (i.e., that could be used as a power source). It consists mostly of silicon, oxygen, and (for the most part) a bit of iron and/or magnesium. None of those materials are radioactive, reactive, or flamable in their mineralic form. Personally, I've never heard of olivine (a pretty benign substance if there ever was one) being used as a power source or in furnace bricks. Do you remember the reference of where you read that?--Will.i.am 10:38, 6 December 2006 (UTC)

(The wiki-n00b, again) Er, sorry, I didn't imply it was being used as a power source, merely a component. Not sure why it's in there. The book I read stating it was used in bricks was an antique 50's era field guide to minerals, so it was probably out dated. The book, I think, was called "Rocks and Minerals" or something bland like that. It was pretty official looking, though, and had an eerie amount of detail for all the components like half-life and cleavage, so I don't think it was just some Discovery Store kids' book. I'll look for it later. -TJ

the most common rock?

This article seems to me to be seriously understating what is an absolutely amazing mineral: if indeed it comprises 50% of the earth's mantle, it's very likely to be the most common type of "rock", or at least of mineral, on earth. Furthermore, it binds CO2 when crushed, thus providing a plausible geoengineering route to reducing atmospheric CO2 levels and removing excess acid from the world ocean.

And, yes, since the reaction is exothermic, it could plausibly be used as a power source (probably most easily in a galvanic cell, given the problems with using a small heat differential to build a heat machine).

I think that's amazing. We tend to think of rock and CO2 both as waste products that have attained their lowest energy state, and that that's simply untrue on such a staggering scale - only a small faction of the world's olivine would be enough to bind all carbon on the planet - is, at least, amazing, and at best an early hint at a chemical reaction that might stop or reverse global warming, if the technological issues can be solved.

I'm putting this here because, frankly, I don't know much about rocks, and the one thing I learned today is that no one else I've ever talked to does, either. I know that mining and crushing huge amounts of rock might be a bit more difficult than it seems to a non-engineer, but the rewards would be huge. why's no one doing it?

92.116.251.251 (talk) 15:54, 4 February 2010 (UTC)

I too, wanted to verify this information. I am at this moment watching NatGeo's Naked Science. In episode 3 of the 2009 season called "Birth of Oceans" a Geologist stated, that Olivine is the most abundant mineral on Earth. Should this be added to this article. Does it need to be further confirmed? I'll get his name when the episode reairs later tonight. Rayfire (talk) 00:33, 23 April 2010 (UTC)

The geologist is Professor Mike Drake.Rayfire (talk) 00:46, 23 April 2010 (UTC)

Comment

earth has been cooling for billions of years. Mg-rich olivine 'freezes' at much higher temperatures than Fe-rich olivine. Ergo, whilst common Mg-rich olivine evidently solidified billions of years ago, coalescing onto crustal formations that human geologists have studied; conversely, Fe-rich olivine may yet be liquid, and account for the bulk of material in the fluid, convecting mantle. 66.235.38.214 (talk) 23:20, 22 September 2012 (UTC)

And ... how would you improve the article? Vsmith (talk) 23:32, 22 September 2012 (UTC)

Using Olivine as a Short-cut to produce hydrogen

As of December 8th, 2013, several general-media reports have cited Olivine as the essential mineral in a new process for producing hydrogen:

"Researchers in France said aluminum oxide speeded up a process by which hydrogen is produced naturally when water meets olivine, a common type of rock, under the high temperatures and pressures found at great depths." -Reuters

The article would be improved by an expert's elaboration on the process and the mechanics of the reaction. Jeffca3 (talk) 04:42, 11 December 2013 (UTC)

Cosmos: Possible worlds

I've never heard of this stuff before, but last week's Cosmos features it as a primary factor for the creation of life. NGT also shows it already being olivine as it emerges from a supernova. That sounds strange to me - wouldn't it form as the minerals coalesce into a planet? Is that worth putting into the main article? Or is NGT overstating things? --Algr (talk) 13:39, 23 March 2020 (UTC)

Contradictory statements about resistance to weathering

The article has seemingly contradictory statements about olivine's resistance to weathering. The first paragraph of the lead states "it is a common mineral in Earth's subsurface, but weathers quickly on the surface", and in the weathering section it states, "Olivine is one of the weaker common minerals on the surface according to the Goldich dissolution series". However in the lead it also states "Olivine rock is usually harder than surrounding rock and stands out as distinct ridges in the terrain" and "Olivine rock is hard and base-rich", and in the uses section it states "In Finland, olivine is marketed as an ideal rock for sauna stoves because of its comparatively high density and resistance to weathering under repeated heating and cooling". How can this be clarified? PaleCloudedWhite (talk) 05:08, 12 June 2020 (UTC)