Ingrid tested the physical properties of a mineral by rubbing it on a white tile. The mineral left a brown mark on the tile. What property was Ingrid testing?

/the trachea, commonly known as the windpipe

the main thing i would use is bricks because if there is a hurricane, there is a great possibility for the house to still stand. and i would also use plexiglass windows instead of regular windows because plexiglass isn't prone to breaking.