Talk:Diamond Dragon/@comment-170.140.105.14-20130403055301/@comment-216.52.207.123-20130403130447

For the curious,

Toughness is a gems ability to resist breaking.

Hardness is a gems ability to resist scratching.

Jade, for example, has a low Hardness (around 6 to 6.5) but one of the highest Toughness ratings (Excellent) - you can scratch the surface, but it won't fracture easily.