Toughness is also a physical property, different from the definition of hardness. Refers to the degree of internal gravity caused by the internal structure of matter. A simple understanding of toughness is the flexibility of matter. This has nothing to do with the hardness of the substance. Of course, what we usually call toughness is solid matter.

Because your classification is jade, let's take jade as an example. Everyone knows jade, white jade. Their hardness is well known. The hardness of jadeite jade is higher than that of white jade, but its toughness is lower than that of white jade. Specifically, jadeite is fragile, while white jade is not fragile.