Overview
About Diamond
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.
Birthstones & Anniversaries
On almost all modern birthstone lists, diamond is recognised today as the birthstone for April. Diamond is also the gem that marks the 60th and 75th wedding anniversaries.
58x Harder
Diamonds are the hardest material on earth: 58 times harder than anything else in nature.
“Lucy” in the Sky
Fifty light years from earth, this star is a 10 billion-trillion-trillion carat diamond.
1 in 1,000,000
The average yield in most diamond mines is 1 part diamond to 1 million parts host rock.
Facts
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Mineral:
Diamond
Chemistry
Treatments
There are a number of processes used to alter the colour or apparent clarity, or to improve the durability of gems.
Learn MoreSynthetics
Some gemstones have synthetic counterparts that have essentially the same chemical, physical and optical properties, but are grown by man in a laboratory.
Learn MoreImitations
Any gem can be imitated – sometimes by man-made materials or by natural materials chosen by man to impersonate a particular gem.
Learn More
Why We Love This Gemstone
Global Language
The 4Cs, created by GIA, are considered the global language of diamond quality.
Carbon
Diamond is the only gem composed of one single element: carbon.
A billion years
Most diamonds formed more than a billion years ago, deep in the earth’s mantle.
Quality Factors
The human contribution to a diamond’s beauty is a well-executed cut.
Clarity

Clarity grades assess the number, size, relief and position of inclusions and blemishes.
Colour

The less colour, the higher the grade. Even the slightest hint can make a dramatic difference in value.
Cut

Cut (proportions, symmetry and polish) is a measure of how a diamond’s facets interact with light.
Carat Weight

Rarity means larger diamonds of the same quality are worth more per carat.
Diamond quality factors: the comprehensive guide
Research
Explore research on diamond history and diamond grading.

The Very Deep Origin of the World’s Biggest Diamonds
Evan M. Smith, Steven B. Shirey, and Wuyi Wang , Nov 8, 2017 Read more in English
Diamonds from the Deep: How Do Diamonds Form in the Deep Earth?
Karen V. Smit and Steven B. Shirey , Feb 1, 2019 Read more in English