What is the best way to see a diamond's fire?

• A. Look at from above with diffuse direct light.
• B. Observe under a microscope.
• C. The best way to see a diamond's fire is to look at the stone face-up while rocking and tilting it at the same time.
• D. The stone should be viewed with the culet facing up.

Answer: (C)

Fire in a diamond comes from dispersion—splitting light into spectral colors as it travels through and exits the stone. To see those colorful flashes clearly, you want to view the diamond in its face-up orientation and gently rock and tilt it. This movement changes which facets the light enters and exits through, maximizing dispersion and the visibility of colored flashes. The standard face-up view with light hitting the crown facets lets you perceive the fire as lively color sparkles, whereas other positions alter the light path and lessen the effect. Viewing under a microscope or with culet-up orientation changes the angle and scale of what you’re seeing, and diffuse light from above tends to wash out the fire, making it harder to observe.