Crystal | Wikipedia audio article

This is an audio version of the Wikipedia Article: Crystal 00:01:38 1 Crystal structure (microscopic) 00:03:47 2 Crystal faces and shapes 00:05:30 3 Occurrence in nature 00:05:39 3.1 Rocks 00:07:31 3.2 Ice 00:07:55 3.3 Organigenic crystals 00:08:15 4 Polymorphism and allotropy 00:09:38 5 Crystallization 00:11:25 6 Defects, impurities, and twinning 00:13:28 7 Chemical bonds 00:14:51 8 Quasicrystals 00:16:01 9 Special properties from anisotropy 00:17:20 10 Crystallography 00:17:46 11 Image gallery Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago. Learning by listening is a great way to: increases imagination and understanding improves your listening skills improves your own spoken accent learn while on the move reduce eye strain Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone. You can find other Wikipedia audio articles too at:    / @wikipediatts983   You can upload your own Wikipedia articles through: https://github.com/nodef/wikipedia-tts "The only true wisdom is in knowing you know nothing." Socrates SUMMARY ======= A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word crystal derives from the Ancient Greek word κρύσταλλος (krustallos), meaning both "ice" and "rock crystal", from κρύος (kruos), "icy cold, frost".Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Examples of polycrystals include most metals, rocks, ceramics, and ice. A third category of solids is amorphous solids, where the atoms have no periodic structure whatsoever. Examples of amorphous solids include glass, wax, and many plastics. Despite the name, lead crystal, crystal glass, and related products are not crystals, but rather types of glass, i.e. amorphous solids. Crystals are often used in pseudoscientific practices such as crystal therapy, and, along with gemstones, are sometimes associated with spellwork in Wiccan beliefs and related religious movements.