The world’s love of diamonds had its start in India, where diamonds were gathered from the country’s rivers and streams. Some historians estimate that India was trading in diamonds as early as the fourth century BC. The country’s resources yielded limited quantities for an equally limited market: India’s very wealthy classes. Gradually, though, this changed. Indian diamonds found their way, along with other exotic merchandise, to Western Europe in the caravans that traveled to Venice’s medieval markets. By the 1400s, diamonds were becoming fashionable accessories for Europe’s elite.
Diamond forms under high temperature and pressure conditions that exist only about 100 miles beneath the earth’s surface. Diamond’s carbon atoms are bonded in essentially the same way in all directions. Another mineral, graphite, also contains only carbon, but its formation process and crystal structure are very different. Graphite is so soft that you can write with it, while diamond is so hard that you can only scratch it with another diamond. More Information on Diamonds can be found here. 
FACTS
MINERAL: Diamond
CHEMISTRY: C
COLOR: Colorless
REFRACTIVE INDEX: 2.42
BIREFRINGENCE: None
SPECIFIC GRAVITY: 3.52 (+/-0.01)
MOHS HARDNESS: 10

-Source GIA

$14,388.25
$891.00
$1,047.00
$1,230.00
$1,257.00
$1,641.00
$2,187.00
$360.00
$540.00
$813.00
$1,233.00
$3,477.00
$645.00
$666.00
$690.00
$699.00
$705.00
$714.00
$717.00