On the AGS Light Performance Ideal Cut Spectrum Which Shape/Cut Exerts the most Fire/Dispersion?

[Cosmetologist]

I've been pondering this question for a while - Which AGS Ideal Branded or Non-Branded Cuts Exerts the most Fire/Dispersion? And In what order would they Rank for Fire & Dispersion alone?

I would've thought the AVCs & CACs are at the top then the AVRs but what would come after that?
Please correct me if I've got it wrong I'm only an Eager Amateur not an expert!!

I know it seems a silly question but I find it Fascinating - I find the whole AGS Light Performance Grading Ideology Fascinating!

 

[Karl_K]

@kenny can tell ya :}

 

[Rhino]

Fire/Dispersion is the quality of fire given within a diamond and is differentiated from sparkle although the two are observed hand in hand in the spot lighting environment.

In general, if the diamond exhibits large flashes and the diamond is cut to AGS Ideal specs, that will exhibit the extremely high quality fire while at the same time exhibiting what would be described as a slower moving scintillation effect.

The more you decrease the size of the flashes, the more you decrease the fire yet increase the speed/amount of the sparkle scintillation.

Ie. The exact opposite of AVC/AVR types would be a Star129. They exhibit little fire because the size of the facets are extremely small on the pavilion yet exhibit the fastest/most sparkle scintillation you'll observe in a diamond. The fire/sparkle scintillation is a fair trade off depending on ones taste.

 

[OoohShiny]

Ie. The exact opposite of AVC/AVR types would be a Star129. They exhibit little fire because the size of the facets are extremely small on the pavilion yet exhibit the fastest/most sparkle scintillation you'll observe in a diamond.

Am I correct in thinking that smaller pavilion facets = smaller dispersion fans?

And lower crowns (with flatter angles of star facets and upper girdle facets) create less dispersion (so smaller dispersion fans), whereas higher crowns (with steeper star facets/UGFs) create more dispersion (bigger dispersion fans)?

So the killer combo for maximum fire would therefore be high crown with large pavilion facets? (so AVC/AVR? )


I recall that John Pollard has previously posted that fire in a MRB can be increased by making sure light paths through the stone are maintained? lengthened? (IIRC??), which is why CBIs have such great fire, but that discussion got a bit technical for me...

 

[AV_]

@Rhino The rule [large facets with fine optical symmetry & particular proportions, therefore fire] does work even for extremes - I recall the Context cut doing this, but eight facets are too few, it would take some playing around to get in its line of fire. More facets are clearly reasonable.


digressing

 

[kenny]

@kenny can tell ya :}

If the question is which shape can have the best fire/dispersion/light return my instinct says the round shape, though I'm not well enough informed to articulate exactly why.
If round is true, I'll bet Karl could explain.

That said, obviously all shapes can be optimized (via design and cutting) for the best light performance for that shape.

 

[Cosmetologist]

Thanks for explaining that in such easy terms @Rhino!

Personally I think it would be really beneficial for prospective Buyers to see in order which of your Branded Diamonds exhibit which Characteristics I.E. Which Ideal Cuts will have more Fire & which ones have a varied Balance of Scintillation/Fire I know it sounds silly but it took alot of Research on my behalf to find basic information I could understand whereas simple chart listing the Characteristics of each of your Ideal Branded Cuts would be super helpful regarding Fire/Scintillation & Cut Characteristics.

 

[Karl_K]

If the question is which shape can have the best fire/dispersion/light return my instinct says the round shape, though I'm not well enough informed to articulate exactly why.
If round is true, I'll bet Karl could explain.

That said, obviously all shapes can be optimized (via design and cutting) for the best light performance for that shape.

Branded Rounds are optimized for white light return. Any ags0 cut will be.
Designs that get ags0 with the best fire/dispersion was the question.

One design that gets ags0 cut is a fireball according to some people.
This was done by making the virtual facets right smack in the middle between large and small relative to the size of the diamond.
Large enough for big fire events, small enough for a lot of them driven by optional angles.

 

[Cosmetologist]

Thank you to both @Karl_K & @kenny for your responses I know it's quite a hard one to answer when specifically enquiring which AGS Ideal cut Stones display the most Fire/Dispersion alone

 

[OoohShiny]

@Rhino The rule [large facets with fine optical symmetry & particular proportions, therefore fire] does work even for extremes - I recall the Context cut doing this, but eight facets are too few, it would take some playing around to get in its line of fire. More facets are clearly reasonable.


digressing

Thanks for mentioning the Context cut!

I wasn't aware of it - it looks like a Point Cut crown with Old Single Cut pavilion??

Diamonds.net - Fancy Shapes Series -- Context Cut

he Context Cut is a registered trademark and patent of Dr. Freiesleben, Munster, Germany. Stone Coast Gems is the exclusive distributor of the cut in the United States and Canada.In 1997, the Context cut won the “Best of the Best Award” for highest quality design in the Design Innovationen...

www.diamonds.net

Graphic from Yoram:

Diamond Girdle - A cutter's compass in the cutting process

Diamond girdle has a significant role in how a diamond is cut. Historically their importance ignored while today girdles act as a cutters compass.

gemconcepts.net