Figure 5
De Boodt, Kepler, Hooke, Huygens and Stensen considered the cause of the crystal shapes to lie within the crystal: stacks of particles, layering of planes, as can be shown by using educational pyramids. Source: Voyage dans le cristal; adapted from Johannes Kepler (1611), Strena Seu de Nive Sexangula; Christiaan Huygens (1690), Opera Reliqua. |