Why are Diamonds always cone/pyramid-ish shaped?

Question

I just wondered this, why are they always like that? i've never seen them any other shape

Answer 1

They come in many shapes !

Basically, the diamond cutter has to determine how to get maximum value per carat by avoiding inclusions and to get maximum size (maximum value per carat times maximum size) out of the rough diamond he cuts. It is his job ! Therefore, he will not be likely to cut thin slices for example. Odd shapes do exist of course, when that shape would be deliberately choses as it offered maximum value.

Rough comes in double pyramids (bases together) called octahedron, or in much flatter shape called macles (many in triangular shape), and in many more complex shapes.

Answer 2

When found in nature, diamonds can be any shape, just like any other rock, and they are not so pretty and shiny when found, and before they are cut and polished.

Answer 3

They are cut to these shapes to get the most facets.  It is the facets that reflect the light and the more you have the more brilliant the diamond will be.  

Answer 4

They only look that way because that is how they are cut.  As the other answer states, they are not at all pretty when they are first found.