unhewable
/ˌʌnˈhjuːvəbəl/Definitions
1. adjective
Impossible to cut or hew; uncuttable or unhackable.
“The unhewable stone wall was a testament to the ingenuity of the ancient builders.”
2. noun
Something that is impossible to cut or hew; an uncuttable or unhackable material.
“The unhewable material turned out to be a type of crystal that was too hard to cut.”