Medicine, crystal and stress are all very different types of what?
Stress ball now available, stress balls are generically known as stress relievers. There are several different types of stress balls that originate from many different countries. The most common type of stress ball in America is the “bean bag” type, commonly known as a “Hacky Sack”. The stress ball that is most common in Australia is the foam type, this type prevents stress through resistance from squeezing the ball. The third type of stress ball is the Chinese form known as the Baoding ball. These are not like the others as these are not squeezable, they are solid, they usually come in
Crystal although each individual sheet is mechanically very strong, the sheets are rather loosely bound to each other. Therefore, the mechanical strength of the material is quite different depending on the direction of stress. Not all crystals have all of these properties. Conversely, these properties are not quite exclusive to crystals. They can appear in glasses or polycrystals that have been made anisotropic by working or stress—for example, stress-induced birefringence. "Crystallography" is the science of measuring the crystal structure (in other words, the atomic arrangement) of a crystal. One widely used crystallography technique is X-ray diffraction. Large numbers of known crystal