Use in gemmology

In gemmology a phenomenon is an unusual optical effect displayed by a gem. Play-of-color, labradorescence, iridescence, adularescence, chatoyancy, asterism, aventurescence, schiller and color change are all phenomena of this type.

Use in philosophy

In philosophy, the use of the word phenomenon differs from other uses in that it refers to perceived events. Phenomena may be perceived through a person's senses or with their mind.

The term came into its modern philosophical usage through Immanuel Kant, where it is contrasted with noumenon (for which Kant used the term "Ding an sich", or "thing-in-itself") or Absolute. Phenomenon and noumenon serve as interrelated technical terms in Kant's philosophy. Noumena, in contrast to phenomena, are not directly accessible to observation. Nowadays, "phenomena" are often, but not always, understood as 'appearances'. These are themselves sometimes understood as involving qualia.

See also

• Phenomenology
• Physical system
• Observation
• Physicalism
• Noumenon
• Epiphenomenon