Siamese cat point, and tortoise-shell ("tortie") point. In the United Kingdom, all pointed Siamese-style cats are considered part of the Siamese breed. In the United States, a major cat registry, the Cat Fanciers' Association, considers only the four original fur colors as Siamese: seal point, blue point, chocolate point, and lilac point. Oriental Shorthair cats with color points in colors or patterns aside from these four are considered color point Short hairs in that registry. The World Cat Federation has also adopted this classification, treating the color point Short hair as a distinct breed. Many Siamese cats from Thailand had a kink
Crystallographic point group known as a crystal class. There are infinitely many three-dimensional point groups. However, the crystallographic restriction of the infinite families of general point groups results in there being only 32 crystallographic point groups. These 32 point groups are one-and-the same as the 32 types of morphological (external) crystalline symmetries derived in 1830 by Johann Friedrich Christian Hessel from a consideration of observed crystal forms. The point group of a crystal, among other things, determines directional variation of the physical properties that arise from its structure, including optical properties such as whether it is birefringent, or whether it shows the Pockels