Crystal

A crystal is a solid material whose whose atoms or molecules are arranged in a repeating pattern.

Crystals are produced whenever a solid is formed gradually from a fluid, whether the formation results from the freezing of a liquid, the deposition of dissolved matter, or the direct condensation of a gas into solid form.

Quartz crystal By Didier Descouens 

Well-known substances that form crystals are table salt (whose crystals are cubes), diamond, and quartz.

In Ancient Rome, wealthy Romans always drank from goblets made from clear rock crystal. They believed the transparent mineral was a safeguard against their enemies, because legend had it that a cup carved from the transparent mineral would not hold poison.

The Roman writer Pliny was amazed that his fellow citizens were willing to pay huge prices for this real crystal, when there was readily available cheaper glass that looked very similar.

Sunglasses made of colored rock crystal are supposed to have been worn in China, during the Ming dynasty (1368–1644). They were popular with judges who believed that the glasses would conceal their facial expressions while questioning witnesses during court sessions.

The study of the growth, shape, and geometric character of crystals is called crystallography. French priest and mineralogist, René Just Haüy (February 28, 1743 – June 1, 1822) founded the science of crystallography after he accidentally broke a piece of calcite and discovered that they cleaved along straight planes that met at constant angles. He broke more pieces to confirm his discovery and developed the theory of crystal structure.

Haüy's law, which describes the relationship between the angles of crystal faces and their underlying lattice structure, is still used today in crystallography.

In 1912, Lawrence Bragg was a research student at the University of Cambridge when he and his father proposed the use of X-rays to determine the atomic structure of crystals. They discovered that when a beam of X-rays strikes a crystal, it diffracts into a pattern of spots, which can be used to determine the arrangement of atoms in the crystal lattice.

This breakthrough discovery, known as Bragg's law, revolutionized the field of X-ray crystallography and opened up new avenues for studying the atomic and molecular structures of materials. For their work, Lawrence and William Bragg were jointly awarded the Nobel Prize in Physics in 1915, making Lawrence the youngest ever Nobel laureate in physics at the age of 25.

In 1982, Dan Shechtman, an Israeli chemist, discovered that certain metallic alloys formed a previously unknown type of crystal structure that he called quasiperiodic crystals. These crystals had a repeating pattern that was not quite periodic, meaning it did not repeat exactly at fixed intervals, but rather it repeated in a more complex and self-similar way.

At the time of the discovery, Shechtman's findings were met with skepticism and ridicule from the scientific community. Linus Pauling, a renowned chemist and Nobel laureate, famously dismissed the discovery as "impossible" and said "There is no such thing as quasicrystals, only quasi-scientists."

Despite the initial skepticism, Shechtman's discovery was eventually accepted by the scientific community and it revolutionized the field of solid-state chemistry. In 2011, Shechtman was awarded the Nobel Prize in Chemistry "for the discovery of quasicrystals" and his discovery led to the development of new materials with unique properties, which have potential applications in fields such as aerospace and electronics.

Henry Ford maintained that eating sugar was tantamount to committing suicide as its sharp crystals cut a person's stomach to shreds.

The Cave of Crystals in Chihuahua, Mexico, contains giant gypsum crystals more than 36 feet long and weighing up to 55 tons. With over 90 percent humidity, a person can only survive exposure in the cave for a short period of time.

Tiny ice crystals fall and join with others to form a snowflake. The size of a snowflake depends on how many crystals hook together.

At the center of almost every snow crystal is a tiny mote of dust, which can be anything from volcanic ash to a particle from outer space.