Cleavage (crystal)

Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite crystallographic structural planes. These planes of relative weakness are a result of the regular locations of atoms and ions in the crystal, which create smooth repeating surfaces that are visible both in the microscope and to the naked eye.

Types of cleavage

Cleavage forms parallel to crystallographic planes:

Basal or pinacoidal cleavage occurs when there is only one cleavage plane. Graphite (the mineral which makes up a pencil lead) has basal cleavage. Mica (like muscovite or biotite) also has basal cleavage; this is why mica can be peeled into thin sheets.

Cubic cleavage occurs on when there are three cleavage planes intersecting at 90 degrees. Halite (or salt) has cubic cleavage, and therefore, when halite crystals are broken, it will form more cubes.

Octahedral cleavage occurs when there are four cleavage planes in a crystal. Fluorite exhibits perfect octahedral cleavage. Octahedral cleavage is common for semiconductors. Diamond also has octahedral cleavage.

Cleavage

Cleavage may refer to:

Cleavage (breasts), partial exposure of the separation between a woman's breasts.

Buttock cleavage, minor exposure of the buttocks and the gluteal cleft between them

Toe cleavage, partial exposure of a woman's toes in shoes

Cleavage (crystal), in mineralogy and materials science, is a process of splitting a single crystal.

Cleavage (geology), Foliation perpendicular to stress as a result of ductile deformation. e.g. shales (shists)

Cleavage (embryo), in embryology, is the division of cells in the early embryo.

Cleavage (fiber), in optical fibers.

Teeth cleavage or tooth cleavage, slang for Diastema (dentistry), the gap between a person's two front teeth.

In cell biology, the Cleavage furrow is the indentation that begins the process of cleavage, by which animal cells undergo cytokinesis.

Bond cleavage in chemistry and biochemistry

Cleavage (politics) The divisions of society that cause people to vote differently

Cleavage (molecular biology), cutting of the 3' signaling region from a newly synthesized pre-messenger RNA (pre-mRNA) molecule in the process of gene transcription.

Crystal

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 is derived 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.

FULL EPSIODE 02 Minerals - Understanding the Earth...

Chemistry(Lec1,Solid Introduction,Crystal Lattice)...

Say Yes The Dress S14E12 # Bling Lace and Cleavage...

Let's Play Nuclear Throne episode 2...

Crystal Rhythm 02 (One Hour Techno Mix)...

Crystal structure...

Vidéo aliexpress juillet 2015...

Mica...

HAUL Aliexpress et Ebay #2...

photo: AP / Laura-Chase McGehee, FILE

Green Party presidential candidate Jill Stein delivers her acceptance speech at the Green Party's convention in Baltimore on Saturday, July 14, 2012.

Hillary and Jill – Jill Stein That Is – Went Up the Hill To…

Edit WorldNews.com 14 Jul 2016

Article by WN.com Correspondent Dallas Darling. Nursery rhymes like “Jack and Jill” have entertained both young and old for centuries ... Indeed, the masses were not only sorely oppressed under their regime, but burdened with falling wages, rising inflation and unfair tax rates favoring the wealthy ... In fact, eight contained information classified at the highest level, or “top secret,” at the time they were sent. Indeed, Mrs ... ....

photo: AP / Lionel Cironneau

People dance during a party for Bastille Day, at Cremat, near Nice, southeastern France, Monday, July 13, 2015.

Many People Reported Dead, Injured After Lorry Strikes Bastille Revelers In Nice

Edit WorldNews.com 14 Jul 2016

Bastille Day celebrations in the southern French city of Nice have become somber following reports of a truck striking members of the crowd, killing at least 30 and injuring hundreds, BBC News said.The incident took place on the famous Promenade des Anglais during a fireworks display. A Twitter image showed about a dozen people lying on the street with some being attended to by rescue personnel, the report said ... We heard some shots....

photo: Creative Commons

Florida, USA Alligator on the St Johns River near Blue Spring. Blue Spring State Park is a state park located west of Orange City, Florida in the United States.

Report: Firefighters Fed Gators That Killed Toddler At Disney Seven Seas Lagoon Resort

Edit WorldNews.com 14 Jul 2016

The resort was where two-year old Lane Graves was killed after being pulled into the water by a gator.Reedy Creek "is the Disney-controlled taxing district that provides government services to the theme parks and surrounding areas,” the report said.Feeding alligators is illegal because it causes the animals to lose their natural fear of humans ... You would figure they would have more common sense than that ......

photo: AP / Jim R. Bounds

Authorities investigate the scene where the body of 5-year-old Shaniya Nicole Davis was found outside of Sanford, N.C., Monday, Nov. 16, 2009. Authorities acted on a tip Sunday and searched a wide area in south-central North Carolina trying to find the 5-year-old girl reported missing by her mother, who has been charged with human trafficking and child abuse involving prostitution.

[VIDEO]: White Man Arrested After Racial Threats To Black Man Near Eugene, Ore.

Edit WorldNews.com 14 Jul 2016

An African-American man says he no longer feels safe living in his neighborhood after an Oregon man allegedly threatened him, according to a Raw Story report Thursday quoting local TV station KEZI. Police told the station Rodney Blomberg was with three men in a truck with a Confederate flag attached to it who approached the victim. The victim told police Blomberg told him black people “get hung in these parts.”....

photo: Creative Commons / Idriss Fall

Dead Boko Haram soldier in Nigeria, killed in March 2015.

Cameroon troops kill, torture Boko Haram suspects: Amnesty

Edit Philadelphia Daily News 14 Jul 2016

LAGOS, Nigeria (AP) - Cameroonian security forces have unlawfully killed dozens of civilians and tortured and forced the disappearances of others in mass arrests of suspects in fighting the Boko Haram Islamic insurgency, Amnesty International reported Thursday ... Amnesty. Advertisment ... ....

search tools

You can search using any combination of the items listed below.

Language:

Sort type:

Arrived Within:

Search Type: