What evidence is there that it isn't?! It is neither a liquid nor a gas.
Sand is a solid.
Sand is a solid, not a liquid.
Sand is a solid, not a liquid.
sand is solid if you look in the microscope it's solid
A grain of sand is a network solid (covalent network solid).
Each grain of sand is a solid.
sand is solid if you look in the microscope it's solid
sand is solid if you look in the microscope it's solid
sand is solid if you look in the microscope it's solid
Sand is a solid due to its molecular arrangement.
Sand is a solid!
it is a solid