Diamond is one of the many best-known mineral.
It is formed under high pressure and may be colourless, yellow, green, blue, or pink.
Each carbon is strongly bonded
to four others to form a tight, rigid structure. This makes diamond extremely hard
and tiny diamond is used as a cutting and drilling tool in industry.
Shown below, in the extreme left, is the "Koh-i-noor". This is claimed to be the oldest large
diamond. It was found in India and after belonging to Mogul kings was presented to Queen
Victoria in 1850. Its cut was unimpressive, so it was recut. The steps in the cutting process
are shown using models.
Step 1: Shaping the rough stone.
Step 2: The top pyramid rounded.
Step 3: Faceting begins.
Step 4: More faceting.
Step 5: Finish product with 58 facets placed with mathematical precision so that light
passing thrugh the stone may reflect with a mazimum of brilliance.
The "Koh-i-noor" was re-cut as a brillant.
Other cut are Marquise, Emerald-cut, Pear-shaped, Baguette.
