I am trying to recreate King Arthur's the Sword in the Stone using chemistry.
I have a couple ideas how this could be done Would any of these work or how it might work? Arthur removes the sword from the stone and is blessed by Archbishop Brice, from Le Livre de Merlin, France, N. (Arras), 1310, Add MS 38117, f. 73v." Caption via the British Library's Medieval Manuscripts Blog.
Unlike this answer: Making a sword in the stone, in a medieval world without magic I am interested how this could have been done with a substance available in 500AD.
What could be smelted or concreted then to allow a sword to be entered into it then allowed to cool or harden with no chemical bond to the sword?
The material of the stone would need to contract as it gets colder to release the sword at a certain temperature, not be so hot during insertion to effect the temper of the sword, and/or allow water or ice to permeate between the sword and stone.
Similar to using whiteout to create a barrier between the soft iron shell and the inside hard steel of a canister Damascus forge could the sword be coated with a whiteout/liquid paper like material that breaks down when wet over time?
An eight-year-old found a pre-Viking-era sword while swimming in a lake in Sweden during the summer. It is relativity intact for being in the water that long. Source: https://www.bbc.com/news/world-europe-45753455
Could water get between a designer stone and the treated sword enough to erode or breakdown the bond between the sword and the stone with little corrosion to the sword?
The simplest way this could be done I can think of is thrusting the sword into a ball of lava rock that meets the edge of an ocean then moved and carved. Over time water and winter loosen the sword.