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Let's Rock => Identifications of Materials => Topic started by: Kosbare on July 22, 2018, 02:39:20 PM

Title: "Smoking" Stone From Africa
Post by: Kosbare on July 22, 2018, 02:39:20 PM

Hello All!

Received a video of these stones that appear to smoke when removed from the water. Has anybody come across these before? Very strange phenomenon but myself and my friends in Namibia would love to know more about this strange material. Check out the YouTube link:

https://www.youtube.com/watch?v=sLieMvJ5dqE

J.P.

Title: Re: "Smoking" Stone From Africa
Post by: lithicbeads on July 22, 2018, 06:21:58 PM

 I imagine it is hydrophane opal which can easily hold 20% water which it easily releases. I had a basketball sized piece of hydrophane break out of a rhyolite egg we dropped off a mining platform on a steep mountain side on a very hot Oregon day. The egg had hit a boulder on the slope and the huge hydrophane which was full of fire was exposed  but by time I got the 40 feet down the hill the opal was turning white  and it had crazed to opaque small white pieces in half an hour.

Title: Re: "Smoking" Stone From Africa
Post by: rocks2dust on July 22, 2018, 08:03:06 PM

I've never seen hydrophane smoke. Could be an evaporite like thermonatrite, which are found in many dried lake environments across Africa. I'm not sure what is in the bucket, which might be contributing to/retarding the chemical reaction upon exposure to air.

Title: Re: "Smoking" Stone From Africa
Post by: Jhon P on July 24, 2018, 10:36:58 AM

I will bet they did something to it to make  it smoke. Maybe dry ice