The rarest diamond colour is the naturally occurring red colour. All naturally coloured diamonds have a further grade designation on this scale:
The Fancy Vivid colour designation is the most expensive grade.
Read more, below.
The rarest color of a diamond is red.
The rarest color for an Aurora Borealis is purple and orange in the aurora australis
Red diamonds are the most expensive in terms of money per carat, since red is the rarest colour of natural diamonds.
'Rare' used to describe a natural diamond describes many diamonds. Red is generally acknowledged as the most rare natural colour in diamonds. Then, the Moussaieff Red, could be called the world's rarest diamond. You can read more about this stone, below.
Several types of diamonds are rare, less than .1% of all natural diamonds. They are each described in the link, below.
Probably a red diamond, since it is the most rare natural colour.
A red diamond is probably the rarest colour for a natural diamond. Flawless diamonds are the rarest in clarity, and large diamonds weighing in excess of 20 carats are rare.
The rarest diamond color is the natural red diamond. Most diamond dealers have never seen one, other than a "red" diamond that was originally congac or yellow color, and was treated to look red. The second rarest is the natural untreated green diamond, then, the natural untreated orange, then the blue and the pink diamonds. The value depends on many other factors however. But colorless diamonds are still the most sought after.
rarest eye color is GREEN
The rarest Pokemon is Dialga
A red one
The rarest color for an Aurora Borealis is purple and orange in the aurora australis
the red diamond
Red is rarest-around 25 percent
Rubies are considered to be the second rarest gem. (The diamond is the first rarest gem)
it is a red diamond
Yellow is said to be the most popular, black in the middle and the rarest color would be chocolate.
Red diamonds are the most expensive in terms of money per carat, since red is the rarest colour of natural diamonds.