Translation of "Dureza" in English

Tienen una dureza tierna.

There is a tender hardness to them.

Debe evitarse la dureza en esos casos.

Harshness should be avoided in those cases.

El grado de dureza del diamante es diez.

The hardness of diamond is 10.

Me ha salido una dureza en la planta del pie.

I have a callus on the sole of my foot.

Tal es la dureza de un diamante que puede cortar vidrio.

The hardness of diamond is such that it can cut glass.

Aún me recuerdo mirando con miedo su rostro surcado a la vez de candor y dureza.

I still remember staring with fear at his face marked with candor and toughness.