India, Sept. 4 -- Of all the jewels in the world, there is a reason diamonds arrest the imagination so completely, and universally.

It isn't just their brilliance. Diamonds resonate with something far deeper.

They are a living manifestation of eternity. They are also a symbol of the power of transformation. The power of time (as well as heat and pressure, of course) to turn something ordinary into something breathtaking.

Most gem-quality natural diamonds were already taking shape deep within the planet billions of years ago. The oldest known diamond, found in Canada, has been dated to about 3.5 billion years ago.

This makes them stunning records of deep time.

The colour of a diamond can be used by scientists to indicate the formation...