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Why Big Price Difference In These Two Stones?


pfq1982
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Looking at BlueNile's diamond finder, I've got two stones that filter through:

 

Stone 1: Ideal cut, 1.87 carat, G color, VS1 clarity, GIA report, $18,823.

 

Stone 2: Ideal cut, 1.86 carat, G color, VS1 clarity, GIA report, $23,303.

 

Stone 1 details: 62.0% depth, 58.0% table, thin to slight thick girdle (Faceted), Exc symmetry, very good polish, very small culet, no fluor, 7.83x7.90x4.88

 

Stone 2 details: 62.3% depth, 56.0% table, thin to slightly thick girdle (faceted), Exc symmetry, Exc polish, no culet, no fluor, 7.81x7.91x4.90

 

What is the big variable accounting for $4.5k px difference? Just the polish stands out, but it's only one step? An help appreciated. Thanks a lot!

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I think there's a decent chance that the first one is simply a typo and that you wouldn't actually get the stone if you asked for it but that's just a guess. The Blue Nile system, for the most part, is simply a virtual consignment deal where someone tells them a stone is available, lists a few stats and at what price. They put a markup on the price and include it on their site for sale. If someone contacts them and wants to buy it they contact the supplier and try to put together a deal. Sometimes it works and sometimes it doesn't. It's a nicely efficient system but it does lead to a certain amount of errors as well as the occasional bargain. If a supplier wants to move a stone quickly for whatever reason they can offer it through BN or one of the similar channels at an attractive price and it's likely to move fairly quickly. Equally likely, they can list a stone that isn't actually available in the hopes that someone will call and then they can try and sell something else entirely.

 

Neil

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Shopping ONLY by price may be harmful to your wallet: Why the price difference?

 

1. Diamond # 1 falls outside the traditional definition of Ideal Cut as mathematically defined by Marcel Towlkowsky in 1919 because his table range was 54-57%. Therefore at 58% you are receiving a discount despite the nomenclature offered by the Vendor. A Vendor can call a diamond anything he likes, doesn't make it so.

 

2. Diamond # 2 is an EX-EX whereas Diamond #1 is EX-VG.

 

3. Check the Cut Grades for both diamonds. Quite possible that Diamond # 2 received an EX Cut Grade whereas Diamond # 1 received a VG Cut Grade.

 

Bottom line question is this: Both diamonds placed side-by-side, could you/would you be able to see a difference and have a preference? Only your visual inspection will answer this question and you possibly could be getting a dynamite diamond ( #1) at a great price.

 

If you can't see this diamond in person you need a picture/data work from a seasoned Diamond Vendor that can call in these diamonds and additionally discern/explain to you the optical nuances of both diamonds. A drop-ship Internet website like Blue Nile can't and won't do this and hence you're shopping blind.

Edited by barry
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Barry, I agree that shopping blind is bad, but I disagree about your explanation of the difference in prices.

If one stone is an EX cut grade, and the other merely a VG- there is a difference in price- but it would not be 20%- especially on a rare stone like a 1.86ct ( a rare size because most times the cutter can change angles only a small amount to get a 2.00ct)

 

In terms of table size, GIA will give an EX cut grade to a 60% table diamond, which is well outside the Tolkowski table range.

GIA's cut grade is not based on Tolkowski standards.

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They are both listed as "ideal cut", though, in Blue Nile. Is this not the cut grade? If not, how can I determine the cut grade?

 

Agree about wanting to see the stones -- I am visiting some jewelers to see the difference between ideal cut vs. exc or vg, all other things equal, vs1 vs. vs2 all other things equal, g vs. f all other things equal, etc. I'm willing to pay a reasonable premium over something like blue nile, but not an unreasonable premium. Return policies on Blue Nile are very good so if the stone isn't as brilliant as one hopes, I can always send it back.

 

Thanks for the help so far!

 

Shopping ONLY by price may be harmful to your wallet: Why the price difference?

 

1. Diamond # 1 falls outside the traditional definition of Ideal Cut as mathematically defined by Marcel Towlkowsky in 1919 because his table range was 54-57%. Therefore at 58% you are receiving a discount despite the nomenclature offered by the Vendor. A Vendor can call a diamond anything he likes, doesn't make it so.

 

2. Diamond # 2 is an EX-EX whereas Diamond #1 is EX-VG.

 

3. Check the Cut Grades for both diamonds. Quite possible that Diamond # 2 received an EX Cut Grade whereas Diamond # 1 received a VG Cut Grade.

 

Bottom line question is this: Both diamonds placed side-by-side, could you/would you be able to see a difference and have a preference? Only your visual inspection will answer this question and you possibly could be getting a dynamite diamond ( #1) at a great price.

 

If you can't see this diamond in person you need a picture/data work from a seasoned Diamond Vendor that can call in these diamonds and additionally discern/explain to you the optical nuances of both diamonds. A drop-ship Internet website like Blue Nile can't and won't do this and hence you're shopping blind.

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GIA does NOT use the term "Ideal", their top Cut Grade is "Excellent" and again, according to Towlkowsky's definition, Diamond #1 is not "Ideal". This is a clear mis-use of the term.

 

Good idea to l@@k at stones and see for yourself.

 

Good Luck.

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Simply translated Neil, we agree right?

Although there may be bargains found on the database lists ( such as Blue Nile) there is a good possibility that one stone ( likely the one that's 20% less than market) probably won't be available.

 

Yes David, we agree. We usually do. Actually it's entirely possible that neither stone is available but the chances are much higher with the ones that are priced out of line with other similar stones.

 

In the case of rounds, 'ideal' in BN lingo means a stone that has received the top cut grade from any one of the 3 labs they use, GIA, AGS or GCAL. With other shapes they use their own internal system based on a few of the major measurements, an approach that all of the major labs, including those 3, have refused to endorse despite quite a bit of pressure to do so.

 

Neil

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Actually the price difference that I see is that the 1.87 ct. is not a GIA EX EX EX and the 1.86 ct. is a EX EX Ex.

 

However neither one are the top in cut grade that I can see. The 1.86 ct. is a little deep for my taste and the 1.87 ct. has a little bit more fat on the pavilion area which may result in not a top sparkler.

 

There are other stones available that are cut better than both of those.

Edited by jan
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GIA does NOT use the term "Ideal", their top Cut Grade is "Excellent" and again, according to Towlkowsky's definition, Diamond #1 is not "Ideal". This is a clear mis-use of the term.

 

Good idea to l@@k at stones and see for yourself.

 

Good Luck.

 

Barry- it seems as though you are mixing terms.

If we are using Tolkowski definition, that would negate GIA's cut grade system who's EX cut grade includes more modern cuts, such as a 60/60.

 

Maybe they would include a 54% tabled diamond- although I feel that looks very small in a modern cut

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Actually the price difference that I see is that the 1.87 ct. is not a GIA EX EX EX and the 1.86 ct. is a EX EX Ex.

 

However neither one are the top in cut grade that I can see. The 1.86 ct. is a little deep for my taste and the 1.87 ct. has a little bit more fat on the pavilion area which may result in not a top sparkler.

 

There are other stones available that are cut better than both of those.

 

Jan, as usual you're quick to offer people diamonds when they come to ask a question- but you're not answering the question.

The difference in the stones ( one has VG polish vs one with EX polish) in itself is no explanation of such a large difference in price.

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The term "Ideal" is correctly identified with Towlkowsky, not GIA, so if a vendor uses this term the connotation is a Table % of 54-57%, not 58% and not a 60-60 stone.

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BN's definitions are arbitrary. They even give Cut Grades to their listed Fancies which are totally meaningless.

 

 

I don't have a favorite Table % size. I look at the entire diamond as Optical beauty can derive from multiple combinations.

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Maybe it's because I' was trained at a time and place where 60% table and depth were considered optimal- but that seems, to my eye, to be a the best proportion.

 

A 54% table can also be quite beautiful. It just looks a little small based on what I grew up with.

 

As far as the cut grades it's really endemic. That's a shame.

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I suspect "training" (in the broadest sense - perhaps taste formation would be a better expression) has a strong impact on our perception of beauty.

 

I was "born" to antique furniture in the UK, where patination and a natural, aged finish are strongly desired. Having moved to Italy (and France is even worse), I often find pieces that are refinished to a high gloss and that I find "wrong". Not necessarily ugly - just not beautiful. Yet they command higher prices than their British equivalent, and many people seem to like them.

 

Back to diamonds, I for example quite like high crowns and smallish tables in rounds - more like an OEC, if you wish. The issue is that to make it really work, the pavillion needs to be cut correctly, and it often isn't.

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I suspect "training" (in the broadest sense - perhaps taste formation would be a better expression) has a strong impact on our perception of beauty.

 

I was "born" to antique furniture in the UK, where patination and a natural, aged finish are strongly desired. Having moved to Italy (and France is even worse), I often find pieces that are refinished to a high gloss and that I find "wrong". Not necessarily ugly - just not beautiful. Yet they command higher prices than their British equivalent, and many people seem to like them.

 

Back to diamonds, I for example quite like high crowns and smallish tables in rounds - more like an OEC, if you wish. The issue is that to make it really work, the pavillion needs to be cut correctly, and it often isn't.

Back in the 80’s, I spend some time living in Japan. At the time, chrome plated steel and vinyl furniture of the type widely sold in the US in the 50’s was all the rage. This stuff was VERY expensive and people were terribly concerned about whether it was ‘genuine’ or a reproduction. I was appalled. It reminded me of the furniture when I was growing up that had been consigned to the basement craft room where you could do finger painting and such without messing up anything important. Were they crazy or was I? I guess that’s where the taste question comes in. At the time I was pretty sure it was them but now I"m less confident. Genuine 1950’s USA furniture was very hard to come by in 1984 Japan and it sold for a huge premium. Presumably the buyers were very pleased with it and gave it a place of honor in their homes so I guess we Americans were dumb for discarding it. I can easily imagine a Japanese mom warning her children to be careful on the expensive furniture and to go play elsewhere. On the other hand, the garage sales of my youth were hard pressed to sell it at any price. I wonder if some ‘genuine’ fingerpaint stains would helped.

 

In hindsight I guess maybe we were both right.

 

 

Neil

Edited by denverappraiser
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Thanks for all the responses so far. A couple questions on what I'm reading... what's an "OEC"? Also regarding talk of 54% tables that tend to have poor pavillions and 60/60 cuts... in the experience of people who look at diamonds every day, what percentages tend to be associated with the most brilliant stone? What tends to be "wrong" about the way the pavillions are cut with a 54% table and what should I be looking for there?

 

Thanks again.

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OEC = Old European Cut. One of the precursors of the modern round brilliant cut, with a higher crown and smaller table than modern cuts.

 

Percentages and proportions as measured by four numbers are by and large only indicative of actual performance; a RB-cut diamond has 57 facets, and all contribute to the overall appearance of the stone. Apparently small deviations in angles and alignment can produce substantial changes in appearance; beware of recipes.

 

In addition, there are personal preferences; some people like broad flashes of white light, others prefer smaller multi-coloured coloured sparkles, others still prefer more clearly visible patterns...

 

ETA: There isn't a single way in which a 54% table stone can be cut; however, given that the general consensus is that tables around 57-58% are the ones that most people like best, 54% would make most experts pay a lot of attention to the rest of the stone. It's not a bad sign - it's just a flag to pay attention whether the rest of the stone "fits" with a smaller table.

Edited by davidelevi
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OEC = Old European Cut. One of the precursors of the modern round brilliant cut, with a higher crown and smaller table than modern cuts.

 

Percentages and proportions as measured by four numbers are by and large only indicative of actual performance; a RB-cut diamond has 57 facets, and all contribute to the overall appearance of the stone. Apparently small deviations in angles and alignment can produce substantial changes in appearance; beware of recipes.

 

In addition, there are personal preferences; some people like broad flashes of white light, others prefer smaller multi-coloured coloured sparkles, others still prefer more clearly visible patterns...

 

ETA: There isn't a single way in which a 54% table stone can be cut; however, given that the general consensus is that tables around 57-58% are the ones that most people like best, 54% would make most experts pay a lot of attention to the rest of the stone. It's not a bad sign - it's just a flag to pay attention whether the rest of the stone "fits" with a smaller table.

 

 

That was an excellent reply David.

 

Putting 57 facets on a diamond is really the key here. It's impossible to tell what a diamond will look like using a few averages of a diamond's table, crown, pavilion. That is because the numbers are only average measurements. For example, a stone will have 8 crown angles, 8 pavilion angles and 8 table measurements that are all averaged to make the numbers you see on the lab report. So it is really not telling you what the facets are doing together to bring the light back to the eye.

 

Initially you can maybe weed out some, however without seeing the diamond itself, you won't know how bright the stone will be.

 

 

It's quite possible to have a stone that is an excellent cut grade with excellent polish and excellent symmetry and not get a very good light performance. I've sent back a few duds that were cut exactly like that. I've also seen a few AGS ideals that were not great too.

 

That is why we check each individual diamond.

Edited by jan
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given that the general consensus is that tables around 57-58% are the ones that most people like best

 

Actually that is not true.

Before GIA started issuing cut grades, when the only credible lab issuing grades was AGSL, it would have been easy to believe that a 60% table was "outside the box"

BUT- GIA's cut grade system was based on many more factors- including human observation. 60 % tables are included in GIA's top cut grade.

I feel that given the opportunity, many more people would be attracted to a 60% table, as compared to a 54% table.

It's just a prettier proportion.

Diamond dealers have always loved 60/60 as a numerical proportion- and with very good reason. Mr Winston was NOT wrong.

 

pfq1982- I do agree with most of what Davide wrote- don;t focus on minutia like pavilions- look at the whole package.

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  • 2 weeks later...

Just wanted to thank everybody for posting -- very helpful. Still trying to find that perfect stone, but I'm lightyears ahead of where I was when I started and posted here.

 

I note nobody asked what the pav angles, crown angles, pav %, etc. were. As Jan mentioned, averages have their limitations (is that how the angles are reported?), but nobody seemed concerned that any of those might be a major outlier.

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GIA and AGS both report angles as the average at 8 main points in the stone (and what's more AGS rounds to 0.1 and GIA to 0.2 degrees), which is another reason why it's relatively meaningless to look at them in isolation, since deviations of the entity of the rounding (never mind the standard deviation) are enough to make significant differences in appearance.

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Just wanted to thank everybody for posting -- very helpful. Still trying to find that perfect stone, but I'm lightyears ahead of where I was when I started and posted here.

 

I note nobody asked what the pav angles, crown angles, pav %, etc. were. As Jan mentioned, averages have their limitations (is that how the angles are reported?), but nobody seemed concerned that any of those might be a major outlier.

 

I noted that the price difference between the two stones as described indicates a major problem someplace- to answer you specifically- it's outside the realm of possiblity that the angles on either of these diamonds could exlain that.

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