Iron-eating Stone, why this phenomena?

[Niboy]

i stumbled on a video on the internet (https://youtu.be/MBeMcgars_w), a stone that melts an iron nail in a few seconds. in another video, it showed there that the iron nail after being exposed to the stone/rock became very brittle. whats the explanation? please help. someone asked me this and i cant give an answer. thank you.

 

 

[Strange]

I assume the"nail" is made of some sort of frozen mixture of water and the stone is warm.

[Moontanman]

30 minutes ago, Strange said:

I assume the"nail" is made of some sort of frozen mixture of water and the stone is warm.

The nail is made of gallium, the rock is warm... 

[Strange]

2 minutes ago, Moontanman said:

The nail is made of gallium, the rock is warm... 

I wish I had thought of that!

[Sensei]

Or nail is made of tin, and rock is warmer than 231.9 °C (that would be the easiest way to make this trick, as tin is widely available on the market).

Or nail could be made of Mercury below -40 C. It has melting point ~ -38.83 °C.

Or nail could be made of Sodium-Potassium NaK alloy. Melting point ~ -12 C.

(that would explain why he is holding nail with gloves, to not start melting it by hand)

 

Edited November 19, 2017 by Sensei

[John Cuthber]

11 minutes ago, Sensei said:

Or nail could be made of Sodium-Potassium NaK alloy. Melting point ~ -12 C.

I rather doubt it could.

Cooled below -12 it would condense water from the air as ice.
When it warmed up + melted the reaction would be rather obvious- probably leading to combustion.