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Tuesday, December 14, 2010

Diamond (gemstone) - Wikipedia, the free encyclopedia

Diamond (gemstone) - Wikipedia, the free encyclopedia

Diamond (gemstone)


Brillanten.jpg
Material
Material properties
Crystallographic defects
Formation and surfacing
The 4 Cs
Carat · Clarity
Color · Cut
Production

List of mines
Diamond cutting
The diamond industry
De Beers

Cultural impact
History · Symbolism
Famous diamonds
Imitations and enhancements
Synthetics · Simulants
Enhancements
See also
Index of related articles
Wikipedia Commons media

A diamond (from the ancient Greek ἀδάμας – adámas, meaning "unbreakable," "proper," or "unalterable") is one of the best-known and most sought-after gemstones. Diamonds have been known to humankind and used as decorative items since ancient times; some of the earliest references can be traced to India.

The hardness of diamond and its high dispersion of light – giving the diamond its characteristic "fire" – make it useful for industrial applications and desirable as jewelry. Diamonds are such a highly traded commodity that multiple organizations have been created for grading and certifying them based on the four Cs, which are carat, cut, color, and clarity. Other characteristics, such as presence or lack of fluorescence, also affect the desirability and thus the value of a diamond used for jewelry.

Perhaps the most famous use of the diamond in jewelry is in engagement rings, which became popular in the early to mid 20th century due to an advertising campaign by the De Beers company, though diamond rings have been used to symbolize engagements since at least the 15th century. The diamond's high value has also been the driving force behind dictators and revolutionary entities, especially in Africa, using slave and child labor to mine blood diamonds to fund conflicts.

The Nobel Prize in Physiology or Medicine 1996

The Nobel Prize in Physiology or Medicine 1996
Peter C. Doherty
Rolf M. Zinkernagel

Peter C. Doherty

Rolf M. Zinkernagel

The Nobel Prize in Physiology or Medicine 1996 was awarded jointly to Peter C. Doherty and Rolf M. Zinkernagel "for their discoveries concerning the specificity of the cell mediated immune defence"