Fulminating Gold

[cliveh]

The fact that Fulminating gold can explode to produce a strange purple smoke has often put me off experimenting with this form of chemistry in photographic processing. Can those in APUG well versed in chemistry and with knowledge about this reaction and its possible use in photographic chemistry, inform if this reaction can be controlled to produce any interesting forms of imagery?

 

[mshchem]

Expensive firecrackers!

 

[koraks]

Expensive, and due to its inherent instability, it's practically unusable.

There are photographic processes that employ gold in the image-forming stage (as opposed to using it as a toner); see e.g. the chrysotype process, and some of its modern variants.

Chrysotype – AlternativePhotography.com

www.alternativephotography.com

 

[Mike Ware]

https://www.mikeware.co.uk/downloads/Chrysonomicon_I_History.pdf

https://www.mikeware.co.uk/downloads/Chrysonomicon_II_Practice.pdf

 

[Ian Leake]

The fact that Fulminating gold can explode to produce a strange purple smoke has often put me off experimenting with this form of chemistry in photographic processing. Can those in APUG well versed in chemistry and with knowledge about this reaction and its possible use in photographic chemistry, inform if this reaction can be controlled to produce any interesting forms of imagery?

I'm not sure if this was posted as a piece of artful trolling, or as a genuine question. On the assumption that it's the latter, here are my thoughts. These are really addressed to people who may see this thread in the future and do something foolish.

1. There is a Wikipedia page that describes fulminating gold, its history and its properties. It's not hard to find. Here's an extract: "Generally, it is best to avoid accidentally creating this substance ... as it is prone to explosion with even the slightest touch."
2. US Patent #730800 (pdf from Google patents) from 1902 in which Paul Schoenfelder described a photographic process based upon fulminating gold. The existence of a patent, does not mean that Schoenfelder had a working process, not does it mean that the instructions given within are complete. In fact old patents were often written in such a way as to obscure the actual process used in an attempt to keep it secret. If you don't believe this, just try reverse engineering Willis' platinum printing patents into a working process.
3. Experimenting with explosives when you know nothing about chemistry is the height of self-indulgent stupidity. Don't do it.

 

[Don_ih]

I'm not sure if this was posted as a piece of artful trolling

Clive is really not anything close to a troll.

 

[cliveh]

Thank you Don_ih.

And thank you Mike and I am familiar with many of the references you make in your book "Gold in Photography." It was also good to see reference to Mrs Fulhame, who is often overlooked in the work she did.

 

[Donald Qualls]

Don't forget there is also a difference between fulminating gold and gold fulminate. In the case of the silver analog, silver fulminate is routinely used in the little "snappers" that are commonly sold around firework dates -- it's dangerous to handle, but not impossible (and each snapper contains something like a milligram in close to a gram of fine gravel). Fulminating silver, on the other hand, forms by accident when making a solution to chemically silver a mirror, and can be so sensitive even in a bottle of silvering solution as to explode on exposure to sunlight. The "fulminating" versions of gold and silver don't even have conclusively known formulae, while silver and gold fulminate are directly analogous to mercury fulminate, and the chemical formula and synthesis are well known (mercury fulminate was used in percussion caps and the earliest cartridge primers in the 19th century).

BTW, the purple cloud is finely divided gold; you can make a suspension of purple gold safely, if you like the color (and don't mind spending your money on gold-bearing reagents).