You will see a picture of the rock and some information about it. Click on the button with the name of the rock.
Try to get a perfect score!
The correct rock was actually .
Granite Basalt Obsidian Pumice Quartz
Slate Schist Magnatite Marble Graphite
Chalk Coal Sandstone Shale Limestone
It doesn't come from China.
I didn't make the image.
It might have some connection to Pi.