Why does light move so slow within a well cut diamond???

Answer 1

I am shocked by the nonsense people answer here. The speed of light has nothing to do with its reflections. And of course it is slower in a diamond than it is within the air, Because diamond is a different medium than air.
The user named "oklatom" is wrong, and so is Karan and all the others so far. On contrary, even just in water, light is already much slower (still way faster than anything else, of course), but in water, its speed droppes from c to about 85 % of c ... that is a lot.
And if there is enough stuff (not only water) then it is even enough to stop light completely.
That's why water is pitch black from a certain depth.

Of course the light in a diamond is slower than in air, because the diamond is much denser than air.

Answer 2

I rather doubt it moves any slower, but it is difficult to measure the movement of light throw the diamond due to the refractive features of the crystal. The light bounces around a lot within the crystal.

Answer 3

The facets have to be cut just right and there has to be a certain number of them (the more facets, the more sparkle). Faceting patterns that work on diamonds have different results on other stones and vice versa. It's one of those things that gem-cutters have to learn by trial and error.

Answer 4

The speed of light is 299,792,458 meters per second, or 186,282 miles per second. Even in a well cut diamond. But you do get sparkle and reflection, and a prism effect that will reflect back various colors of light. (And to think, it is just coal under pressure.)

Answer 5

Because the density of the diamond is too high and light faces too many reflections and obstacles...

Answer 6

the light actually mves with the same speed but due to very sharp surface angles the light suffers various reflections and refractions and therefore takes a long time to come out

Answer 7

Because of the way the facets are cut, then can't travel in a straight path, they bend and curve.