superhard
adjective
- of an extreme level of hardness
Wiktionary
adj
Etymology: From super- + hard.
- Having a very high hardness.
- Highly strengthened against attack.
“a superhard missile silo”
- Having a hardness between that of boron nitride and that of diamond.
noun
Etymology: From super- + hard.
- A tyre whose compound is harder than a normal hard tyre.