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Formicaite. β-formicaite & α-Ca-formate. Mineral or not?

We publish an article of Roger Warin. He was President of the ’Association des Géologues Amateurs de Belgique’ (AGAB) for 50 years, and currently, he remains the editor of the monthly magazine AGAB-Minibul.

This paper was edited in AGAB-Minibul, 55, 4, p.89-100 (2022). Thank you very much Roger for your contribution to FMF.
https://www.agab.be/


”Following his analysis of this polymorph of calcium formate α-Ca(HCO₂)₂, Dr César Menor-Salvan recently (May 1, 2021) introduced in FMF his discussion about its anthropogenic or biogenic origin ( A new mineral: alpha-calcium formate ). So is it a mineral species or not? This question has been latent for many decades. Aren't we talking about kidney stones or more elegantly, nephrolithiasis (from lithos, the stone)?

In French, the vernacular term is "calculs au reins" (from the Latin calculus, the pebble).

In a first article I recall the brilliant demonstration of Cesar Menor (et al.) by commenting on it with words from the chemist, a keen lover of mineralogy. The various compounds of the same nature are compared and we are surprised to find that some of the species at the border of two concepts have received the noble status of mineral and others have not, just as deserving...

Then, carried away by these ideas, I wrote a second article on the chemistry that exists in space, more precisely in the cold parts of young nebulae (for reasons of thermodynamics). I noticed that the first molecules that formed were organic and not mineral!

I show there that the amino acids are not the bricks of Life, but already large "prefabricated", much simpler bricks, like formic acid.

Passionate about meteorites (thin sections) I already realized that the universe is incredibly young, about 3 times the life of the Sun.

This is the reason why Thermodynamics can be expressed with brilliance today, since 3 Ga on Earth”.

Roger Warin

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[alfredo]

Very interesting article, and interesting crystals. Thank you!

One thing I'd like to point out is that solubility in water has absolutely no influence on whether a substance qualifies as a legitimate mineral species or not - There are hundreds of water-soluble species. The article hints that this might be one criterion (but perhaps I have just misunderstood the author's intent).

But anthropogenic origin "should" disqualify a mineral from consideration as a valid species. Unfortunately (in my opinion) there are already far too many mineral species whose creation has been "assisted" by human activities, and the IMA simply accepts the opinion of the proposal submitters without doing any investigation themselves about origin, natural or otherwise. And so we end up with highly dubious things on the list, like diaoyudaoite and dellagiustaite... basically crystallized industrial waste. Or the recent potassium permanganate from Egypt - highly dubious. As for Alkali Lake in Oregon, how can one trust anything from a known toxic waste disposal site? (See "Alkali Lake Chemical Waste Dump" on Wikipedia.)

[Cesar M. Salvan]

[alfredo]

Cesar, I hope you stay healthy and don't get sick from touching material from that site!

[Cesar M. Salvan]

Thank you Alfredo!. I feel good so far, but after the covid situation and all, that site pollution is the least of my problems, I am afraid!.

Anyway, it is a reasonable concern; so, during our study of the samples and its possible origins, I extracted and analyzed it by MS in order to find possible pollutants or its derivatives produced by abiotic degradation or bacterial metabolism, and haven't found significant quantities whatsoever. So, the samples are quite safe, in case anyone bought one and feel concerned. If anyone is curious, I could share here some analyses.

[Jordi Fabre]

[Roger Warin]

Hello Alfredo, Cesar, Jordi,

Thank you for your feedback.
But I remain a real geologist at heart.
I am opposed to the extension of the nomenclature to artificial inorganic and organic species, be it Egyptian permanganate or cubic zirconia. This is the domain of inorganic chemistry and not that of mineralogy.
On the other hand, extraterrestrial minerals that are almost impossible on Earth or exceptional, are mineral species (schreibersite, troilite, moissanite, for example). Moissanite SiC or silicon carbide, does not exist on Earth. Its type locality is the Great Meteor Crater, Az.
I make the difference between what Nature creates spontaneously in a young nebula and the residues of chemists.
Now it happens that formic acid is one of the true elementary bricks of Life. And by disintegration of Life, we find again this brick. It appears spontaneously in the T Tauri TW Hydrae nebula, one of the closest to the Sun. What is surprising, formic acid is formed in a quantity equivalent to the quantity of methanol deposited on ice crystals at 77°K (-196°C) and 10E-7 mbar. Everything is deposited on grains of dust which agglomerate in comets, the importance of which is known for the seeding of the Earth with water and organic initiators.

Calcium formates are obviously known to physical chemists. There are 4 allotropes, α, β, γ, δ. The γ and δ phases are only stable at high temperatures.
In α-formicaite, a stable polymorph like β-formicaite, the origin of the formate anions must be considered. It is obviously biogenic, but the formate anions belong to mineral, pre-organic chemistry that have already been found in a young nebula.
In conclusion, the decomposition of plant debris leads, in the absence of bacteria killed by the Alkali Lake pesticides, to the elementary bricks of biochemistry, the formates. Human intervention is limited to the destruction of bacteria whose food is formic acid.
If species had to be discredited, it would be all oxalates, urea… but not formates.
I think Cesar can present his presentation to the IMA right away, because the next Alkali Lake may located in Russia.

Did I convince you?

Roger.

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