DIAMOND GETS DARK UNDER HALOGEN LIGHT

[frazer25]

I BOUGHT A DIAMOND SIGHT UNSEEN THAT IS EGL CERTIFIED TO BE F IN COLOR SI1 IN CLARITY AND THE CUT, POLISH AND SYM ARE VERY GOOD. IT LOOKED GREAT IN THE BOX BUT WHEN I PUT IT UNDER HALOGEN LIGHT THE DIAMOND BECAME VERY DARK, ALMOST BLACK LOOKING. THE JEWLER DOESN''T BELIEVE ME. ANYONE KNOW WHAT''S GOING ON?

 

[valeria101]

NO, diamonds do not become black... but they can only return whatever light is available, so weaker lights make them sparkle less, or loose face for good. Well, it is the change in lighting conditions that did the trick. Some diamonds return more light to the viewer than others (this is the main topic on PS, as if you didn't know), depending on how they are cut. The less light the stone returns, the more it's appearence is influenced by the intensity of light around it. This is why all diamonds sparkle in a jewelry store window, but not all keep at it on the street... Some halogen lights (those with very 'cold' light) are particularly good ate making diamonds look dull.

Hope this helps... but there muct be another way to describbe the thing... Otherwise it sounds like the stone becomes opaque and black like coal when taken out of the magic box, and it can't be THAT bad!

 

[StevL]

Remember a diamond looks at light from every angle above, when you have one (or a few) point light sources the diamond only has the points of light to return. The diamonds mirrors see everything else as being dark, and you get the dark reflection.

Hold a mirror down low and point it to your lighting, you will see the mirror will be darker where the spot light isn't reflecting. Diamonds do the same thing.

This is normal in diamonds, and even more so with the better cuts. Sounds crazy but it's true.

The best lighting I have ever seen is a checker board design overhead light that GIA was selling years ago. This light was called the "Diamond Lux". Today the Isee2 looks at diamonds in a similar way. The checker board lighting gives light and dark spots, think of the dark areas as contrast in the diamond.

Not to worry, your diamond sounds normal