Is this cut too deep to sparkle?

[kenny]

http://www.fancydiamonds.net/view_diamonds/4544.htm

I know nothing about cushion cut proportions, but 3.40 X 2.67 X 2.29 mm seems very deep.
I realize FCDs are cut to maximize the color intensity but good light performance (though it doe not drive up the value like good color) is nice to have too.
My fancy intense green round has both strong color and astonishing cut and fire, and it is a marvel to behold.
Expecting good light performance from an FCD cuts the needle in the haystack in half, and pours more hay on too.

So, you cut experts ... can you tell by the pics and proportions if this will be a lifeless (though beautifully-blue) diamond?

 

[chrono]

Kenny,
My calculation of the depth came up to about 70-ish% which isn’t too horrible in the coloured gemstone department so I don’t know if it was a mistake in the listing which shows 85.8% depth. Depth isn’t the primary measurement for determination of light performance but the entire package of how it facet relates to the other. There just isn’t enough information to figure out if it’s going to be a super sparkler or not. It doesn’t look to be too dark which I think a dark toned stone tends to show less fire. Sorry I’m not more helpful as I’m not a cut expert.

 

[PrecisionGem]

I think on stones that small, cut doesn't really make too much difference.

Seems like a lot of $$$ for something you need a magnifying glass to see. You could get one hell of a colored stone for that price.

 

[LD]

I agree with Chrono. It's darker than your green and therefore will probably have less sparkle. I wouldn't worry too much about depth but if you're looking for sparkle then you may be better with a lighter colour. Have you asked the vendor how it performs?

Just curious but are you thinking of buying another blue? I thought you were looking for other colours?

 

[T L]

I have a colored diamond that's cut a little too deep, it's around 60 points, and I feel it would be more lively if it were cut shallower. However, the deep cut was probably done to intensify the color a bit and save weight.

 

[movie zombie]

each to their own, Gene!

MoZo

ps yes, that kind of $ could buy an delicious stone of color not of the diamond family.

 

[kenny]

I think on stones that small, cut doesn't really make too much difference.

I respectfully disagree.
I've bought 8 FCDs now, all very tiny.
The light performance of them varies tremendously and not always inversely proportional to color strength.

Another way to look at it is in small stones light performance is MORE important.
Small rocks need all the help they can get.
Sure, in larger rocks it is easier to notice the light performance but there is better and worse light performance even in melee size 2 pointers.

I believe the 85.8% is accurate, 2.67 x 0.858 = 2.29

There is a huge price increase pending any day now so I'm looking at pricey colors, and stones.

Yes the depth is certainly to amp up the color to the vivid grade, and the color itself is wonderful IMHO.

 

[kenny]

You could get one hell of a colored stone for that price.

This IS one hell of a colored stone.
Besides, I have good macro gear.
Size isn't always everything.

 

[kenny]

each to their own, Gene!

MoZo

ps yes, that kind of $ could buy an delicious stone of color not of the diamond family.

Yeah, last year I briefly considered looking for a Kashmir sapphire till I learned more about the market for such colored gems.
I like the transparency of Internet-published prices instead of prices that are only revealed in secret after the seller has a chance to size you up.

I'm not trying to get the market to change to accommodate Kenny.
I'm just explaining why colored gem vendors lost me (and probably others too polite to speak up) to the more-transparent FCD market.
Perhaps if they got with the times (IMHO) I'd wander into their waters.

 

[minousbijoux]

I think Kenny's original question was about the cut and whether the depth would limit the light return and therefore sparkle. I am no expert, but this is what I have noticed regarding colored stones, mind you, not diamonds. Yes, I too, calculate the depth at about 86%. From my experience, in most stones I've seen that tends to limit the light return. However, in some stones with a high crown, it can make the stone sparkle a lot. In other words, it depends on where the depth is. If its mainly in the pavillion, then the angles will probably be too deep for good light return, but if some of that depth is up top, then the angles are okay, the light bounces back and sparkles. I've noticed this most with sapphires and was just noticing it in another of my stones recently, maybe a spinel or tourmaline.

[now I'll quietly clasp my fingers in my lap and wait to get shredded by the real experts...]

 

[chrono]

MB,
You are quite right in this. A high crown stone is going to show more sparkle than a low crowned stone so it matters where the depth lies. However, again, a lighter toned stone is going to sparkle more than a darker toned stone if all else is equal (crown, depth an all).

 

[kenny]

Thanks I'll try to get a side view pic.

Yes stronger color attenuates light; that's a given, but still, cut is cut and strong-color diamonds can be well or poorly cut when it comes to light performance.
I've seen it with my own eyes in my own collection.

 

[VapidLapid]

I agree with Chrono, there's not enough information. Where is the extra depth, in the pavilion, en über thick girdle, in the crown or equally distributed?
If the extra weight is mostly in the crown and girdle then I think it could be very sparkly indeed. Also that depth % is calculated for the short side. Calculate the % for the long side then take the median % as an indicator of performance



edited for speling

 

[LD]

I know it's difficult to tell but from the face on picture it does tend to suggest that it has a decent height crown.

 

[Michael_E]

can you tell by the pics and proportions if this will be a lifeless (though beautifully-blue) diamond?

I don't think that it'll be a blazing ball of fire. If you look at where most of the light has to originate to reach your eyes you'll find that it has to come from pretty low on the horizon...definitely not where you want it to be coming from. You also have an odd looking color zoning going on which makes me think that most of the color in that stone is way down in the culet. Maybe I'm wrong and it's just some odd light bouncing going on, but you really need several side views to see how the color is really distributed in this stone.

Yeah, last year I briefly considered looking for a Kashmir sapphire till I learned more about the market for such colored gems.
I like the transparency of Internet-published prices instead of prices that are only revealed in secret after the seller has a chance to size you up.

I think that you're looking at this in an odd way. The internet as a selling platform for diamonds has changed dramatically and it used to be much as you are describing the colored stone world. The colored stone world, on the higher end, probably won't change significantly since it is very hard to make things which exist in relative rarity into a commodity. Most of the internet sites which show prices, have prices which variable depending on if you are in the trade, if you are a long term customer and what sort of prospects the seller may have with you for future sales. This can't change much, since the sellers have to offer better pricing to their long term wholesale accounts, even if they are selling at retail levels on-line. I'm not sure just what you mean by "transparency", but if you mean that all price level get shown on-line, I don't think that it's ever going to happen, (probably not with diamonds either, as they have varying price levels, knowledge of which is related to your level of "buying power"). Everybody's always "sizing" everyone up and I think always will be.

 

[kenny]

Thanks Michael.

 

[movie zombie]

i remember that thread, kenny. completely understand your switch to FCDs. in some ways, i think the hunt is easier when you have what you term "transparency".

and i think michael e is right, too: the high end business re color stones is not going to change that much. i believe Gene addressed that in kenny's thread as well. how a color stone can become tainted for lack of a better word once a price on certain stones is revealed.

MoZo

 

[PrecisionGem]

As far as using depth as a percentage to determine if a cut is good, this can really only be done for a controlled design, and in 1 material. Almost always this controlled design is a standard round brilliant, this is the design you see published values for crown height, table diameter etc. ONce you move to a different design, these numbers are meaning less.

Last night I cut a stone, and the height was 52% of the width. This was the correct height for this design. Tonight I'm working an a stone, same material, and the height is 70%, its a different design. This one is a round by the way. Now a SRB (standard round brilliant) for the same material, the correct height is 63.6%, but one of my favorite round cuts the height is 81%. As you can see, these numbers become meaningless, unless you are referring to the exact same design. Now if someone had a SRB, and it was 81%, then it would be too deep for the given material.

The best thing to do with any stone is trust your eyes. How does it look to you. I'm assuming with this diamond Kenny you can return the stone? Just be careful you don't drop it in the carpet, or you'll never find it.

 

[Largosmom]

Kenny, I don't have any advice for you regarding the blue diamond...it's lovely. However, I don't see why you cannot work with a trusted vendor to get yourself a high-end gorgeous sapphire if you want to. You trust your diamond vendor and the diamonds have their grading reports. Work with a vendor whom you respect as much as you do your diamond vendor IF you want that sapphire still. I do enjoy your colored diamond collection too, but I hate to see you limited to buying such little stones forever when you can also have a nice big honkin' colored stone too if you like. Ya gotta have something you can see and enjoy with your bare eyes!

Laura