what would cause a diamond to have no fire?

[intherough128]

I noticed today when I was looking at a diamond in person that the diamond just didn't sparkle, or have any fire. I don't know the specs of the stone, except that it was my friend who was recently engaged, so the ring should be clean since it is new.. any ideas on what causes a ring to just not sparkle, or minimally sparkle?

 

[Harpertoo]

poor cut or clouds/inclusions.
I worked with a women who had a good sized emerald cut. I always thought it was dirty and was dying to clean it, but turned out it was just not a good stone.

 

[TC1987]

No-fire can be just the proportions of it: The cut is strongly biased toward brilliance (white light) and not toward fire.

Lackluster or lifeless is just leakage and poor cut / make. Or cloudy stone, as was already pointed out. A woman I used to work with had a huge marquise, very white. But it apparently lacked any scintillation whatsoever. She wore it when first engaged and then I noticed she never wore it much after marriage. I presume she just quietly put it away because it wasn't cut very well.

 

[MissGotRocks]

A diamond can get dirty very quickly - they are oil and grime magnets. A well cut stone will still have some sparkle when dirty though so I would imagine it is a poorly cut stone.

 

[kay1]

Hmm, interesting. So i'm sure everyone has seen the basic diamond diagram where it shows you a shallow cut or deep cut stone and how it won't reflect back out to the viewer, and i get that = light return.

But what particular aspects of the cut give you scintillation and fire? I've seen on the HCA tool where it's very possible to have excellent in light return and one other category but not the third, so what aspect of the cut actually makes that difference?

 

[Dancing Fire]

A flat top stone with no crown height.

 

[kenny]

Poor cut.
Dirt, yes a diamond can get filthy quickly … hair spray/gel … hand lotion … soap scum.
I clean my diamond a couple times a day.

The lighting may also be the reason.
Colored fire, dispersion, only happens when the light source is relatively small, such as spot lighting like those small halogen bulbs, direct sun.
Actually the best lighting ever was from rows of fluorescent tubes on a very high ceiling in a 99 cent store.

The cleanest, best-cut diamond in the world will give off no fire when it is under soft even lighting.

 

[braga123]

Poor cut.
Dirt, yes a diamond can get filthy quickly … hair spray/gel … hand lotion … soap scum.
I clean my diamond a couple times a day.

The lighting may also be the reason.
Colored fire, dispersion, only happens when the light source is relatively small, such as spot lighting like those small halogen bulbs, direct sun.
Actually the best lighting ever was from rows of fluorescent tubes on a very high ceiling in a 99 cent store.

The cleanest, best-cut diamond in the world will give off no fire when it is under soft even lighting.

OMG! I was tempted to start a thread on "show me your ring at the 99 cents store!"

 

[intherough128]

Very interesting, thank you all for your responses. As Dancing Fire mentioned,her stone does appear to be very flat in the setting. You can't really even see the crown of the diamond, maybe that could be it as well as the poor cut/clouds etc. I have seen it in many different kinds of light so I just assumed it had something to do with the diamond rather than the lighting.