The classes themselves change. This site grows and transforms. It is a witness. Examining crystals you should find more than you expect. The very form and process of crystallization encourages this.
Crystals reveal much in their patterns, flaws, conductivity, growth, cleavage, refractive index.
The limits of what can be learned and shared are delineated by eye and brain. But they too can be crystals. Living, not living. Not a thing. That is its nature and essence.