Labels: Address , Canada , Contact , Corporate , Corporate Headquarters , Corporate Office , customer service , phone number , Review , Reviews , TD , TD Bank , Toronto.
A mineralâs hardness is related to the strength of its weakest bond, and minerals may have different hardnesses in different directions. For example, kyanite has a hardness of 5.5 if scratched lengthwise, but a hardness of 6.5 if scratched crosswise (numbers in Mohs scale). Since covalent bonds are stronger than ionic bonds, minerals in which covalent bonds dominate will be harder than those in which ionic bonds are prevalent.
The hardness of a material is measured against the scale by finding the hardest material that the given material can scratch, or the softest material that can scratch the given material. Mohs' original scale of mineral hardness is as follows: To give some examples from everyday life, a fingernail has a hardness of 2;