DIAMOND FACTS

- Chemical composition: Carbon (C)

- Crystallization: Isometric

- Crystal habit: With well-developed crystals

Specific gravity: 3.5

- Hardness: 10! Diamonds are on the hardest level of the scale!

- Color: Colorless, white, yellow, blue, and rarely other hues

WEIGHT: 45.52 carats
DIMENSIONS: Length 25.60 mm / Width 21.78 mm / Depth 12.00 mm
CUT: Cushion antique brilliant with a faceted girdle and extra facets on the pavilion.
CLARITY: VS1. Whitish graining is present.
COLOR: Fancy dark grayish-blue

The Legend-

The name "Diamond" comes from the Greek word "adamas" which means unconquerable. Both the Greeks, and the Romans believed that diamonds were the tears of Gods, and they also believed them to be specks of falling stars, which fell from above. The hardest substance known to man, diamonds have long been revered for their strength and beauty. Today, the diamond symbolizes love, strength and beauty, and the diamond engagement ring remains one of the most enduring symbols of love.

Diamond Formation-

How Diamonds are formed: Over huge spans of geological time, accumulations occur in a few different ways. The first is soot, which is pure carbon (burned plant material on the earths surface); coal, which is mostly carbon and comes from buried plants over 15km deep; and graphite, which is derived from coal, which has been buried even deeper in the crust. Unbelievable pressure, and mind-blowing temperatures are necessary to cause the formation of diamonds, instead of forming simply the plentiful graphitic form of carbon. The “upper mantle” (around 150-200km deep in the earths crust), are where diamonds can be formed. Sometimes, diamonds form at greater depths around 700km!

Diamond genesis model, showing mantle source regions for kimberlite magma and diamonds.

• A) Peridotitic diamonds (P-type) – these come from peridotitic source rocks in the upper mantle. They are generally composed of olivine, ortho- and clinopyroxene, chromite and pyrope garnet
• B) Eclogitic diamonds (E-type) - type diamonds are derived from eclogitic source rocks in the mantle. These are biminerallic rocks composed of pyrope-almandine garnet and omphacitic clinopyroxene
  So these two P & E-type source rocks act as both an indicator and supplyer of diamonds typically found in kimberlites.

Diamond genesis model, showing the start of a kimberlite's ascent.

Physical properties of diamonds-

Diamonds are made up of carbon (C), and are an isometric mineral. Diamonds are the hardest natural substance known! Diamonds have an absolutely perfect cleavage parallel to octahedral faces (which can be then sawn or broken). To cut a diamond, one must use another diamond on a spinning horizontal plate.

How are diamonds used?

Diamonds have many uses. Many people generally think that the only use for a diamond is in jewlery. However, only 20% of diamonds mined are actually used for jewlery, where as 80% are used for industrial purposes (diamond cutting, bearings for labratory instraments, etc).

Impacts Of Diamond Mining-

Conflict Diamonds: In many places in Africa (mainly South Africa) the diamond industry has been responsible for many human rights abuses. Innocent civilians have no where to turn since even their bribed government abuses them, even to the extent of death. [To read more, click the link entitled, "did someone die for that diamond?]

Technology & Diamonds-

The New Age of Diamonds: Cubic zirconium is a thing of the past, are you ready for what's coming next?! Scientist are very close to making real diamonds, by placing pure carbon, in a device which can replicate the enviornment nessisary to make a diamond! Scientist have been trying for years, but now the only thing stoping them would be the De beers mafia! They've produced these diamonds already, very slowly of course, but flawless, and unditectable from the real thing!

-- What does this mean? Not only are diamonds the hardest substance known, they also have the highest thermal conductivity. Shockingly high levels of heat can move through a diamond and not damage it one bit! Since microprocessors run extreamly hot as it is, diamond microchips (although impossible becasue of scarcity, and high prices) are the answer! They can handle much, much higher temperatures, allowing them to run speeds that would before, liquify the primitive silicon processors of today!

Famous Diamonds: The Hope Diamond

The hope diamond is by far one of the most famous diamonds of all time. It's history begins with a french merchant traveller named Jean Baptiste Tavernier. He sold the diamond to King Louis XV in 1668, in the rough. Before King Louis XV had the diamond recut, it measured an astounding 112 3/16 carats! The court jeweler's recutting of the diamond resulted in a 67 1/8 carat piece of perfect pure carbon! The "french blue" was stolen in 1792, and was later discovered once again recut in London. Kink George IV became the next owner, untill his death in 1830, where it was privatly sold to Henery Phillip Hope. It was Henery who bestowed the diamond with it's title as The Hope Diamond. Since then the diamond passed through the hands of many famous and powerful people. Pierre Cartier, the prestegious jewlers, who's brand of jewlery still bear the Cartier print today. Mrs Evalyn Walsh McLean bought the diamond after Cartier reset it as a head piece on a three-tiered circlet of large white diamonds in 1911. Harry Winston bought the diamond next, and kept it untill November 10, 1958, when it was donated to the Smithsonian Institution.

Literature Cited

• Did someone die for that diamond? - Amnesty Int'l
• Hope Diamond - The Smithsonian Institution
• Zales
• Ohio History Central
• Diamonds in the Rough
• Diamond Index
• South Africas best friend

Link to other Student Web pages for 2004 Earlham Physical Geology

Copyright © 2004 Earlham College. Revised April 26, 2004 . Send corrections or comments to parkero@earlham.edu