So I found a cool picture on like of some Mistborn glass knives and showed them to my friend. He thought looked cool but that the blades of the knives were the wrong colour (they were clear glass). He thought they should be black (obsidian). This sparked a dumb argument and we now want a definitive answer.
Are all Mistborn knives obsidian or are there some obsidian ones and some glass ones?
Please settle this stupid fight.