FMF - Friends of Minerals Forum, discussion and message board

[Barry Flannery]

Hi,

I'm wondering if anyone has ever used ammonium thioglycolate for the treatment of pyrite rot? The only references I could find online were for the chemical ethanolamine thiogylcolate, which I imagine is different?

If someone could give me concentrations and cleaning procedures for the ammonium thioglycolate version, it would be much appreciated and save me needless trial and error.

Thanks,

Barry

[lluis]

Hi, Barry

Well, in the case of ammonium thioglycolate or ethanolamine thioglycolate what could work for pyrite rust is the thioglycolate, that acts as a mild reducer and passes Fe3+ to Fe2+, that is more soluble.
Ethanolamine could act as a better complexing agent than ammonia, but nothing extremely wonderful.

I would suggest as mild agent the solution of sodium bicarbonate/sodium citrate/sodium hydrosulfite, that act also as a reducing agent, being the citrate a far better complexing agent.

Take in account that the glyoclate is what is used as hair remover…Not a very good idea to play with it (corrosive, bad smell,….)

With best wishes

Lluís

[Barry Flannery]

Lluís,

Thank you for your message. The specimens I am looking to clean would contain various carbonates and galena. Are you suggesting using a mixture of sodium bicarbonate/sodium citrate/sodium hydrosulfite or just each separate treatments?

Regards,

Barry

[Barry Flannery]

In addition to that I would prefer to use a non aqueous solvent (I don't want to provide water or dissolved oxygen that will cause further rotting), is there any solvent that will dissolve your alternative solution?

Thanks,

Barry

[Colleen Thomson]

Hi Barry,
thyoglycolate (and thyomyaglycolate) are active ingredients in perming solution used by hairdressers and readily available from any hairdressing suppliers.

i did use this method of pyrite preservation many years ago (being a hairdresser, access to the material was easy!!) - however, results can be inconsistent.

I will need to get back to you as to the method used, as it was so many years ago I've forgotten! Maybe someone else could help out here?
Probably not much help -but good luck anyway!

[GneissWare]

if you google ethanolamine thioglycolate, there are several good descriptions of its use in stabilizing fossils. I've never tried it on mineral specimens.