Types
What type of rock can you make a blackboard out of?
Slate
what is slate used for
blackboards
what type of rock can you make a counter top out of?
granite
what is obsidian for
making knives
what can you use to make stairs?
marble
what is marble used for
it was used to make stairs
what do you use for a blacktop?
Basalt
what is used basalt for
blacktops
what was used to make knives?
Obsidian
what is granite used for
making counter tops