What is the crossword answer for the clue: Symbol of hardness

NAILS - a 5 letter word may be the answer you are looking for!

GRANITE - a 7 letter word may be the answer you are looking for!

CASTIRON - a 8 letter word may be the answer you are looking for!

IRON - a 4 letter word may be the answer you are looking for!

STEEL - a 5 letter word may be the answer you are looking for!

Symbol of hardness

4 Character Answers:

IRON

5 Character Answers:

NAILS

STEEL

7 Character Answers:

GRANITE

8 Character Answers:

CASTIRON