Therefore, metameric fibres cannot be distinguished neither macroscopically nor microscopically. A single-phase system at equilibrium has a homogeneous composition macroscopically. This approach is nevertheless valuable because it can deal well with some macroscopically observable phenomena. The physics of macroscopically observable fluctuations is beyond the scope of this article. Under such an equilibrium assumption, in general, there are no macroscopically detectable fluctuations. Because not all the diseased tissue is visible macroscopically, complete excision is uncertain. Some adenomas are too small to be seen macroscopically but can still cause clinical symptoms. In handsamples, macroscopically visible staurolite crystals are of prismatic shape. "Sporothrix" infection presents macroscopically with nonspecific symptoms. Phases do not need to macroscopically separate spontaneously. This can also be seen macroscopically on brain tissue. In the bulk phase, the surfaces appear to control some of the macroscopically observed properties. Here formula 55 is a macroscopically small energy interval that is kept fixed. Here formula 26 is a macroscopically small energy interval that is kept fixed. Macroscopically, graupel resembles small beads of polystyrene.