Instance of: http://www.w3.org/2004/02/skos/core#Concept
Subject Field unknown
Is Reference of Hardness-en#Sense
Härte-de#Sense
Hardheid-nl#Sense
Dureza-pt#Sense
Dureté-fr#Sense
Hårdhed-da#Sense
Durezza-it#Sense
Hårdhet-sv#Sense
Σκληρότης-el#Sense
Dureza-es#Sense