not capable of being changed into something else
"the alchemists were unable to accept the inconvertible nature of elemental metals"
Untransmutable refers to something that cannot be changed, altered or converted into a different form, state, or nature. It is often used in the context of physical substances or elements, but can also be applied to abstract concepts like values or principles.
Chambers 20th Century Dictionary
un-trans-mū′ta-bl, adj. that cannot be transmuted.
The numerical value of untransmutable in Chaldean Numerology is: 6
The numerical value of untransmutable in Pythagorean Numerology is: 1