Sounds like you have your work cut out for you! Wow. I can help with one word:
obsidian is basically volcanic glass, though it is has a "chemical composition" like granite. It can sometimes run from green to red in color, it is most commonly black. The materials can be made very sharp. It has been found on archeological digs from cultures of the past, but it can sometimes be found also on a surgeon's table because it can be sharper and much thinner than steel. I would assume, then, that the extreme heat of the volcano makes this "glass" much stronger than the glasses we drink from.