Why is obsidian used for so many weapons even though it is very fragile?

Question

I’ve been coming across videos of people breaking obsidian chunks to make arrowheads but could never find the answer why it could be broken with light hits with a rock, and then not break when in use with said weapon.

In: 564

Answer 1

Regarding your concerns about breaking it, search an image of Macuahuitl, it was an ancient Aztec weapon that had individual obsidian blades, this weapon was brutal and effective. Also, the arrangement of the obsidian teeth allowed for them to be substituted individually if needed.