Diamonds by Definition

What is a diamond?

Diamond is the hardest natural substance known to man and the only gem that consists of a single element.

Diamonds began forming over three billion years ago as pure carbon crystals buried 100 miles beneath the earth’s surface. Under the force of intense heat and pressure, these crystals hardened and became embedded in kimberlite, a form of igneous rock. Diamonds are very rare; over 250 tons of kimberlite ore must be mined and processed to produce a 1-carat gemstone. In some cases, erosion in the kimberlite caused diamonds to be released from the ore.

This resulted in a secondary deposit called “alluvial” diamonds. These diamonds flow toward the sea and settle in riverbeds, often far from their original source.

When diamonds are mined, they look like clear or colored crystal rocks and are referred to as "rough". Diamonds were first mined in India over 3,000 years ago. Today, Africa, Australia, Russia, Brazil, and Canada are sources of commercial deposits of diamonds.

Kimberlite

Kimberlite is a type of potassic volcanic rock best known for sometimes containing diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an 83.5-carat (16.7 g) diamond in 1871 spawned a diamond rush, eventually creating the Big Hole.

Igneous Rock

Igneous rock (derived from the Latin word igneus meaning of fire, from ignis meaning fire) is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava. Igneous rock may form with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.

Alluvial Diamonds

Alluvial diamonds is the term used to describe diamonds that have been removed from the primary source (Kimberlite) by natural erosive action over millions of years, and eventually deposited in a new environment such as a river bed, an ocean floor or a shoreline.