The key point here is that in the traditional sense, "states of matter" refers to solid, liquid, gaseous, or plasma states- that is, it assumes a large number of atoms or molecules, yielding a macroscopic ensemble of them.
Now, how big is "large"? Note that a solid cluster of gold atoms consisting of ~tens to hundreds of atoms will exhibit some types of quantum behavior that a cluster of ~billions of gold atoms will not. Note also that a liquid cluster of water molecules consisting of ~tens of molecules will not have a well-defined surface energy, something that a cubic centimeter of water in a test tube will definitely possess.
This means that "large" means "macroscopic".