Less hard, to be more precise [1]. “Strong” and “weak” are way imprecise terms in engineering.
The simplest example is whether it’s strong under pressure (a brick is, a rope isn’t) or under tension (a rope is, a brick isn’t), but there are tons of other properties that are an indicator of strength of a material (https://en.wikipedia.org/wiki/Strength_of_materials), and this may beat diamond in some of them.
[1] reading Wikipedia, even that isn’t simple: “There are three main types of hardness measurements: scratch, indentation, and rebound. Within each of these classes of measurement there are individual measurement scales. For practical reasons conversion tables are used to convert between one scale and another.”
Less hard, to be more precise [1]. “Strong” and “weak” are way imprecise terms in engineering.
The simplest example is whether it’s strong under pressure (a brick is, a rope isn’t) or under tension (a rope is, a brick isn’t), but there are tons of other properties that are an indicator of strength of a material (https://en.wikipedia.org/wiki/Strength_of_materials), and this may beat diamond in some of them.
Reading https://en.wikipedia.org/wiki/Material_properties_of_diamond, diamond isn’t particularly tough, and we don’t really know its tensile strength, so this is less hard, but may have higher toughness or higher tensile strength.
[1] reading Wikipedia, even that isn’t simple: “There are three main types of hardness measurements: scratch, indentation, and rebound. Within each of these classes of measurement there are individual measurement scales. For practical reasons conversion tables are used to convert between one scale and another.”