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MineralsArsenolite

30th Aug 2022 04:09 UTCIris (Xinyue Ma)

Newly discovered Arsenolite from Hechi, Guangxi, China, Raman Shift result here. And the red substance is Realgar. Search mineral id ENP-6JW for more pictures

30th Aug 2022 05:07 UTCHerwig Pelckmans

Realgar, Arsenolite

Crassier Saint-Pierre, La Ricamarie, Saint-Étienne, Loire, Auvergne-Rhône-Alpes, France

Dear Iris,

For sure an interesting specimen, and you have made excellent photos of it.

There is no doubt the minerals are indeed arsenolite and realgar.

However, I do have second thoughts about how this specimen was formed.

From what I see, the realgar crystals are rounded, and the arsenolite crystals do show skeletal growth; both indications that these crystals were formed at elevated temperatures; the arsenolite possibly from an arsenic rich gas.

This makes me think the specimen might have formed on a burning coal mine dump, very similar to what happened in France. See the photo above, and also click on the location name for more info.

In any way, your specimen is very beautiful and a nice addition to your collection, even if it is not 100% natural.

HTH

Cheers, Herwig

30th Aug 2022 09:23 UTCIris (Xinyue Ma)

Dear Herwig，

Thanks for replying !

I'm here to provide more photos of Arsenolite and Realgar of the same batch of specimens. As you can see here, there are leaf-like Realgar crystals which I believe is also some sort of skeleton crystals. And there are tiny Arsenolite crystals on top of it. I agree with your idea that it is the arsenic rich gas that formed Arsenolite. I have discussed with my friend several weeks ago who had bought these specimens directly form the miners. Actually, these specimens was discovered in March, but due to it's vulnerability(It's impossible to mail) and the stupid COVID policy in China, I didn't receive it until August when my friend carry one by himself to my city. According to what my friend said, the locality is actually a Realgar mine that has been mined for decades. These special crystals are accidentally fond when miner were mining for

Realgar, as the miners have little knowledge about what they have found, they posted them on social media and we noticed them. We also tested the samples in lab to prove the species. So, I tend to believe these crystals were formed together with the Realgar mine. I also suspect these crystals could be the result of mining Realgar, I'm not sure how they mine, but if fire is used to burn the rocks, there might be possibility that the beautiful crystals are not purely natural. The miners say it's their first time to discover such crystals, but due to their lack of knowledge on minerals(These miners are relatively less educated and even not sure what they are mining for according to my friend), they might simply neglected Arsenolite before. Since I can only post one picture in each reply, I'll post more pictures later for further discussion. It's really fascinating to discover such beautiful Arsenolite in China, and I am really surprised. This might be the most surprising discovery for me this year. I do wish more of us can see these beautiful crystals.

Cheers, Iris

30th Aug 2022 09:25 UTCIris (Xinyue Ma)

Photo of yellow Arsenolite on top of leaf-like Realgar

30th Aug 2022 09:26 UTCIris (Xinyue Ma)

Photo of leaf-like Realgar

30th Aug 2022 09:27 UTCIris (Xinyue Ma)

Photo of leaf-like Realgar

30th Aug 2022 09:28 UTCIris (Xinyue Ma)

Photo of colorless Arsenolite on top of leaf-like Realgar

30th Aug 2022 09:30 UTCIris (Xinyue Ma)

Photo of light yellow Arsenolite

30th Aug 2022 09:33 UTCIris (Xinyue Ma)

Transparent Realgar crystals.

30th Aug 2022 09:33 UTCIris (Xinyue Ma)

Photo of colorless Arsenolite on top of leaf-like Realgar

30th Aug 2022 11:28 UTCFrank K. Mazdab 🌟 Manager

Iris (Xinyue Ma) ✉️

These miners are relatively less educated and even not sure what they are mining for according to my friend

Yikes... hopefully your friend has imparted on those miners that arsenolite is quite poisonous, and that they should be taking necessary safety precautions while working in the mine.

While we get many posts here from collectors that worry about the perceived dangers of minerals in their collections, working in a mine with exposures of water-soluble arsenolite constitutes a true hazard.

30th Aug 2022 12:05 UTCIris (Xinyue Ma)

We've warned the miners what they are facing with, and also they do have protection gears when mining. It's really tough job to work in these mines

30th Aug 2022 12:53 UTCPaul De Bondt Manager

Comment removed, not geology related.

30th Aug 2022 14:05 UTCRuggy Holloway 🌟

Iris,

You are right to be suspicious as to their origin as they look like vapor deposition products resulting from fire-

The fire at the Whitecaps mine, Nevada produced similar specimens

30th Aug 2022 14:25 UTCDavid Von Bargen Manager

There are also smelters at Hechi (antimony and lead) and the area has been polluted.

1st Sep 2022 02:32 UTCIris (Xinyue Ma)

Comment removed, not geology related.

30th Aug 2022 09:35 UTCPaul De Bondt Manager

Thank you Iris,

Could you explain the geological context of that locality, please?

Keep safe.

30th Aug 2022 11:34 UTCIris (Xinyue Ma)

Paul De Bondt 🌟 Manager ✉️

geological context

Dear Paul，

I'm not major in geology, so it is hard for me to explain the geological context. I'm actually an undergraduate student major in computer science who has only been collecting minerals for 4 years. I'm good at chemistry and crystallography, but geology is what I am unfamiliar with. I'm reading geology textbooks, but for now, I can't help you with the geological context. I wonder if you can find articles about this region on the Internet, they might help. I also don't know where the locality exactly is, the only information is the Arsenolite comes from a Realgar mine in Hechi city, Guangxi province, China

Cheers, Iris

30th Aug 2022 12:39 UTCRobert Nowakowski

Hello Iris

The very first photo in this thread is already in mindat with public approval. But locality is only listed as Hechi. Could you improve this with the mine name. Then arsenolite could be added to the revised locality.

Bob

31st Aug 2022 03:02 UTCIris (Xinyue Ma)

Update!

IMPORTANT!!!

I asked the miner for the exact locality of these specimens.

It is Wuxu Mine, Beixiang, Jinchengjiang District, Hechi, Guangxi

Should be here on this mindat link

Shuiluo Mine (Wuxu Mine), Beixiang - Furongchang ore field, Jinchengjiang District, Hechi, Guangxi, China

30th Aug 2022 18:02 UTCDr. Günter Grundmann 🌟 Expert

Dear All!

I am sure that all the red-orange laminated crystals in the photos shown here are not realgar but crystals from the bonazziite-alacranite solid solution series.

I am afraid that the precise determination and identification of arsenic sulphides is an extremely difficult task. The table below shows the natural crystalline arsenic sulphides:

alacranite,

bonazziite,

orpiment,

dimorphite I,

dimorphite II,

duranusite,

pararealgar

realgar (low)

realgar (high)

uzonite.

In addition, there are a variety of yellow, orange, and red X-ray amorphous arsenic sulfide glasses that are still largely unexplored, with names like "revoredite" ("A black to red natural Pb-As-S glass. Not accepted as a proper species; composition near PbAs4S7; a continuous series from Pb2As2S7 to As2S3 seems likely.")

It is extremely difficult to decide whether the arsenic sulfides mentioned were formed (sublimed) without human intervention on a burning coal heap, or at a volcanic solfatara, or whether they were artificially produced in a sublimation furnace together with arsenic oxides. If you want to find out more about this topic, you should study the following publications (that's no joke!):

https://www.researchgate.net/publication/233713763_Current_Research_on_Artificial_Arsenic_Sulphide_Pigments_in_Artworks_A_Short_Review

https://www.researchgate.net/publication/263714439_'Artificial_orpiment'_microscopic_diffractometric_and_chemical_characteristics_of_synthesis_products_in_comparison_to_natural_orpiment

https://www.researchgate.net/publication/263446611_Types_of_dry-process_artificial_arsenic_sulphide_pigments_in_cultural_heritage

https://www.researchgate.net/publication/361824629_Der_Arsenbergbau_ZuckenhutStrassegg_BreitenauGasen_Steiermark_Osterreich_Archaologische_und_mineralogische_Untersuchungen_zur_Herstellung_von_kunstlichen_Arsensulfiden_In_res_montanarum_622022_107-1

Bindi, L., Pratesi, G., Muniz-Miranda, M., Zoppi, M., Chelazzi, L., Lepore, G.O., Menchetti, S. (2015) From ancient pigments to modern optoelectronic applications of arsenic sulfides: bonazziite, the natural analogue of β-As4S4 from Khaidarkan deposit, Kyrgyzstan. Mineralogical Magazine: 79(1): 121-131.

Bonazzi, P., Bindi, L., Olmi, F., Menchetti, S. (2003) How many alacranites do exist? A structural study of non-stoichiometric As8S9-x crystals. European Journal of Mineralogy: 15: 283-288.

In view of the partially identical or very similar chemical composition, an exact analysis of the arsenic sulphides is only possible with a combination of X-ray diffractometry, Raman microspectroscopy and electron beam microprobe. Accordingly, there are numerous incorrect determinations and namings on mindat.org.

31st Aug 2022 02:56 UTCIris (Xinyue Ma)

Thanks for explaining!

It‘s also the first time for me to know these uncommon species of arsenic sulphides. I will try to read the publications you provided to try to understand them.

Here is the Raman Shift result of the red leaf-like crystals which I assumed as Realgar, hope it helps!

31st Aug 2022 08:45 UTCDr. Günter Grundmann 🌟 Expert

Dear Iris,

Many thanks for your Raman shift graphics. It seems to me that your Raman graph is still too imprecise, i.e. the peaks are too close together in the graph,

to be able to reliably distinguish between the individual phases.

Please compare our paper dealing with applications of Raman microspectroscopy to sublimed arsenic sulphides. I failed to include this publication in my last post.

Here is the missing link:
https://www.researchgate.net/publication/263445121_The_rediscovery of_sublimed_arsenic_sulphide_pigments_in_painting_and_polychromy_applications _of_Raman_microspectroscopy

Best regards,

Günter Grundmann

13th Sep 2022 08:45 UTCHerwig Pelckmans

The latest issue of Lapis magazine (Sep 2022, page 61) has an advertisement by Jürgen Tron for:

"Arsenolit Realgar Wuyu China"

I don't know if "Wuyu" is a typo or not, but it sure resembles the Wuxu mine we have on mindat.

I'm still wondering if these specimens are natural or man made.

For now, I added arsenolite to the list of minerals for Wuxu. Realgar was already listed.

Cheers, Herwig

13th Sep 2022 22:41 UTCDr. Günter Grundmann 🌟 Expert

I would like to point out that the mineral species arsenolite is easily soluble in water. There is generally high humidity underground in a mine. The sharp-edged "arsenolite" crystals shown in this discussion would be dissolved there in a very short time.

It follows that the specimens shown here and in the Lapis magazine (Sep 2022, page 61) are very likely to have been artificially produced. Then, by definition, these are not mineral species, but artificial products.

I urge all those interested in this subject to study the publications I quoted above, and

especially this one:

https://www.researchgate.net/publication/263714439_'Artificial_orpiment'_microscopic_diffractometric_and_chemical_characteristics_of_synthesis_products_in_comparison_to_natural_orpiment

Example:

Pure arsenolite crystals are colorless transparent. The light yellow "arsenolite" crystals shown above are stained by microscopic arsenic sulfide glass spherules as they can only be formed by sublimation (please compare page 136, figures 2a and 2b)

24th Sep 2022 12:11 UTCIris (Xinyue Ma)

Dr. Günter Grundmann 🌟 Expert ✉️

sublimation

This should be Wuxu which in Chinese is 五圩, Wuyu is a common error that the word 圩 looks really similar with other words in Chinese that reads as yu(like 于/吁/纡)

25th Sep 2022 05:25 UTCHerwig Pelckmans

Iris (Xinyue Ma) ✉️

This should be Wuxu

Thanks for letting us know, Iris!

Cheers, Herwig

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