Help! - How To Whitening Fossils With Ammonium Chloride

[Sylvestersen]

Hi

Does anyone have any practical experience of how to whitening fossils with ammonium chloride.

The technique I wish to lear more about is the one where the fossilis is covered with chloride smoke. This coating should eliminates reflections, translucency and color variations, and easily removed by simply blowing on it.

[Auspex]

Here you go: LINK

[Nandomas]

I see this whitening process is easily reversible. Is there any trick to make this process permanent? I was totally hooked by the white color of the Synarmocrinus cobbani crinoid in the pdf

Thanks

[Nandomas]

Nando,

The Ammonium Chloride coating is hygroscopic, meaning it will take moisture out of the air to dissolve. A trick you could use to make it "permanent" is keep the coated specimen in a sealed dry atmosphere with some other substance that more aggressively grabs moisture. Not very practical, but it's a trick that would work.

Thanks fossilcrazy... a part to stay in a dry desert with a dehumidifier ON, I don't see other solutions any suggestion?

[Sylvestersen]

I see this whitening process is easily reversible. Is there any trick to make this process permanent? I was totally hooked by the white color of the Synarmocrinus cobbani crinoid in the pdf

Thanks

I think the beautu of this process is that it is easy to remove. to make it permanent? way not use spraypaint

[Nandomas]

I think the beautu of this process is that it is easy to remove. to make it permanent? way not use spraypaint

It's not the same. The ammonium chloride process enphasizes the contrasts and the shadows, the paint spray flats everything.