If you are in a jewelry shop browsing for a gift for yourself or a loved on, or perusing jewelry ads, you may come across the word "fire" to label a diamond. What does that mean? That the diamond is hot? As fun as a magically warm diamond would be, fire used in reference to diamonds actually means the refraction of light that occurs through a diamond. This creates a band of color like a rainbow. Greeks of the classical period believed that this rainbow fire was a tiny encapsulated portion of the eternal burning of love.

It is best to look for a diamond's fire in places where the light is low, like over a candle light dinner or in a soft-lighted parlor. Exactly how much fire you will see is dependent on how the particular diamond is shaped. More traditionally shaped diamonds look like they have more fire than diamonds shaped in the modern style, because they have exaggerated angles at the crown, and flat, tabular facets. Some other things to consider when you are looking for fire are brilliance and scintillation. Brilliance is a measure of a how bright a diamond is, and how much interior contrast it presents. This affects how much light returns to the viewer. Brilliance is sometimes called return-of-light in the industry. This is what gives diamonds their trademark sparkle, and is what most people are immediately attracted to in the stones. Hence, many gem specialists believe that it a stone's most valuable aspect.

Scintillation comes from the Latin for sparks or embers. For diamonds, scintillation is the way in which light scatters off the surface of stone when it is in motion. Brilliance and scintillation are similar, but the former refers to the light reflected while a diamond is sitting still. Both of them are distinct from fire, which is the reflection of light but about a stone's rainbow making refractions of light.

When a diamond is fashioned into its shape, there are certain decisions that have to be made. Shape determines the amount of fire and brilliance a stone will have, and no stone can have it all. So gem specialists must often choose one or the other. The current trend is to cut stones to enhance their brilliance rather than to increase their fire.

Of course, fire, brilliance, and scintillation are important, but the most important thing is how a stone seems to you. When you are choosing a diamond for yourself, the most important thing is that you find that special something in it. If the stone has all the fire, scintillation, and brilliance in the world, if you don't find it appealing it is worthless to you.