Shedding light on the subject...

To be beautiful a diamond must be bright, colorful and sparkle like crazy - period the End.

The best cut diamonds balance all three factors. If one predominates, then the other two will suffer or simply go away in our visual perception. When all three are equal, then and only then - we'll see them all. That's the nature of the human eye.

We can isolate and feature any factor by controlling the light source. Whether our lighting is by candle, bulbs or the Sun, the visual impact depends entirely on the focus and intensity of that light.

Candlelight is superb. Its low-level "pinpoint" flicker highlights all three of the factors of diamond beauty at the same time. It dramatizes diamond's capacity to return more light than anything else in the room - brightness. Its tiny flame fuels distinct separation of light into highly visible spectral prisms - colorfulness. Its motion excites sparkle.

It may seem counter intuitive, but a great way to show-off brightness is actually on an overcast day - intense very highly diffused light. The diamond will appear bathed in soft light - reflected back to your eye in a bright and soothing manner. Such lighting masks both prismatic effect and sparkle.

It's equally ironic that my favorite place to reveal all the colors of the rainbow in a diamond is under a shade tree on a clear and sunny day - intense multiple pinpoints of light. Each drop of light that rains between the leaves, will display its own visibly distinct rainbow in the diamond. As the wind blows, the dancing leaves stimulate dramatic sparkle.

As for direct sunlight, I've been taught to avoid it like the plague – it’s too intense and obnoxious. Direct sunlight causes overexposure. That's why they invented sunscreen and Ray Bans!

Put a diamond in direct sunlight and it'll hit your eye with the intensity of a flashbulb. I'm not lying. Don't stare or your eyes and brain will go ape. Close-up the glare will block a clear and distinct view of your diamonds performance. But I guarantee you, at arms length you'll catch amazing flashes of color and brightness that can be overwhelming.