Ive been looking for marquise info on the Pricescope for the past few months and have only just come across this very useful post from ColoredGemstoneNut. Is it possible to add this to the knowledge section of the site or have it as a sticky as I think it would be really useful for other people who are looking into buying a marquise:
Marquise Diamonds
Overview:
Here''s a general overview of this particular cut...
Finding the best cut marquises can be a little more difficult than searching for a round. Some of the same basic principles apply in finding a beautiful stone. When searching out a marquise, you not only have to find the best crown/pavilion relationships but you also have the length/width ratio to consider as well. The magic lies in the relationship between the crown/pavilion angles and that is much more important than the table/total depth relationship which seems to be emphasized more often.
The shape & overall brilliancy are important aspects in finding a nice “make“. The length to width ratios vary in marquise diamonds and the proportions will as well. One true method of finding a shape that appeals to your eyes is “looking” at many different stones.
Some Things to Look out For:
"Bow-ties"
Bowties are not necessarily a bad characteristic on marquise cut stones, but how glaringly obvious or the dark presence which is often a phenomenon in this cut can make it look flat or dull in the center.."
A Bow-Tie" look is formed and found right around the culet area in fancies that are cut with 6 main pavilion facets and result in a ''dark'' look as you view the stone face-up.
Really deep stones, with shallow crowns can be flat and lifeless. When the marquise is cut shallow, it makes the stone appear watery in the center, but it also helps to eliminate the “bowtie“ affect.
When a skilled cutter is cutting a marquise a balancing act is presented in that to completely cut a “Bow-Tie” out you end up with a flat looking lifeless stones, and if you leave “Bow-Ties” in with the black line readily noticeable you have a stone worth far less. If the cutter cuts the pavilion shallow to remove it the stone''s "sparkle" looks flat.
The deeper the pavilion is cut the more prevalent the bow tie appears. Ideally, the bowtie should be minimal without shallowing the pavilion.
The trick is in the proper combination of table, crown height and pavilion depth. Even if a marquise is cut "perfectly" it will still have a bowtie.When a skilled cutter executes the right cutting combinations, bow-tie''s are not seen and you get a great looking marquise.
Girdle Area:
Very thin or extremely thin near the "points" is a no - no. On fancy shape diamonds, if the report says thin, you need to find out where the thin section is located. Thin girdles around the head of marquise shapes might lead to chipping and fracturing.
Very thick and extremely thick also require some scrutiny on fancy shapes and can affect overall size (too thick would be a stone cut with extra weight in the girdle).
Shopping by the Numbers:
A good general rule of thumb in searching for any diamond, particularly a fancy-cut stone is to not solely rely on searching out a stone solely based on the numbers. Two marquise stones which generate the same numbers can have dramatic differences in light return and visual performance.
With this said, one route to take in initially weeding out stones by evaluating the numbers is as follows:
A good reference can be found for fancy shapes at Dave Atlas’s website www.gemappraisers.com listed by clicking on the “AGA DIY Cut Grading” link and selecting marquise.
After initially looking at these charts, my advice is to get a sarin or megaScope reports on marquises that "look" good by the parameters set forth in these charts, which also have a solid grading certificate from one of the reputable labs like AGS, GIA, or HRD..etc.Get a good general idea of what you are looking for as far as color and clarity. Getting a vendor to supply you with this information might be a daunting task at first, but there are plenty of vendors who have access to this information and you should insist on being supplied with it in picking out possible stones.
The next step is to arrange to ''see'' these diamonds and determine how the numbers stack up to your eye. This will be the most important task in picking out your stone. Consumers have many different taste which vary from person to person.
The following chart was posted by Barry of Super-B-Cert in which he outlines guidelines in ensuring some of the most brilliant marquise stones:
Length to Width ratio: at least 1.8/1 (2:1 is optimal).
Table Range: 57% to 68%
Depth: 62% " 75%
Crown height:11% " 15.6%
Girdles: Medium to slightly thick
Be cautious with extremely thin to very thin girdles
as this may exacerbate chipping and fracturing.
Finding Length to Width Ratio: You would take the measured length of the stone in millimeters and width of the stone in millimeters, dividing the length by the width and that will give you the length to width ratio.
The following outline concerning ( length in mm and width in mm) for a marquise is described and directly quoted from RockDoc Bill Lieberum who is a leading edge appraiser and can be contacted at consumersgemlab.com.
“The measurements ( length in mm and width in mm) for a marquise is going to vary based on four basic factors.
1. Length to width ratio. There are long thin shaped marquises as well as short "stubby" one. The cutter fashions the stone based on retention of weight of the rough diamond crystal, and the removal of inclusions within it.
2. The crown height. There are steep crowns and shallow crowns and those that are "just right". The height or shallowness of the crown will have an effect on the length and width of the stone.
3. Girdle Thickness - The thickness of the girdle ( edge of the stone) also "adds weight" to the stone, and would "subtract" from its length to width ratio.
4. Pavilion Depth - This is an important area. 2/3''rds of the weight of a diamond is usually located in its belly. So the deeper the pavilion depth is the small the face up outline will appear. The cutter can fashion a deep stone that looks smaller face up which depending on HOW DEEP its cut, can detract from its appearance or he can cut a flat thin stone where the face up appearance looks larger, but usually this causes the stone to have an over brilliant, flat and dull appearance. Cutting too deep will make the "bowtie" look more predominant.”
Key points to Remember:
Symmetry grades in Fancies is not as important or critical as it is in rounds.
On fancy cuts the numbers ( proportions ) are not dependably predictable relevant to its quality of appearance and light return. For instance there are "dead stones" with great numbers, and great looking stones which fall outside the "suggested" parameters. There is no reliable consistency on what the numbers should be, rather stones which fall in certain parameters will most likely produce a more appealing diamond.
Fancy shapes depend greatly on the pleasing nature of their outline shape. A marquise can be pointy or fat until near the points. This makes a difference in how the marquise cut looks to your eye. There are certain aspects of cutting and artistry involved beyond length, width, depth and percentages.
Marquise cut diamonds are cheaper than rounds which are in higher demand and you can save 20% + on a marquise diamond which falls in the same weight range for the pricing of typical rounds. You can get more for your money, buying a marquise stone.
It is a good idea in getting the stone examined by a qualified appraiser who knows the nuances involved with cut grading a fancy.
Hope This Helps...
Marquise Diamonds
Overview:
Here''s a general overview of this particular cut...
Finding the best cut marquises can be a little more difficult than searching for a round. Some of the same basic principles apply in finding a beautiful stone. When searching out a marquise, you not only have to find the best crown/pavilion relationships but you also have the length/width ratio to consider as well. The magic lies in the relationship between the crown/pavilion angles and that is much more important than the table/total depth relationship which seems to be emphasized more often.
The shape & overall brilliancy are important aspects in finding a nice “make“. The length to width ratios vary in marquise diamonds and the proportions will as well. One true method of finding a shape that appeals to your eyes is “looking” at many different stones.
Some Things to Look out For:
"Bow-ties"
Bowties are not necessarily a bad characteristic on marquise cut stones, but how glaringly obvious or the dark presence which is often a phenomenon in this cut can make it look flat or dull in the center.."
A Bow-Tie" look is formed and found right around the culet area in fancies that are cut with 6 main pavilion facets and result in a ''dark'' look as you view the stone face-up.
Really deep stones, with shallow crowns can be flat and lifeless. When the marquise is cut shallow, it makes the stone appear watery in the center, but it also helps to eliminate the “bowtie“ affect.
When a skilled cutter is cutting a marquise a balancing act is presented in that to completely cut a “Bow-Tie” out you end up with a flat looking lifeless stones, and if you leave “Bow-Ties” in with the black line readily noticeable you have a stone worth far less. If the cutter cuts the pavilion shallow to remove it the stone''s "sparkle" looks flat.
The deeper the pavilion is cut the more prevalent the bow tie appears. Ideally, the bowtie should be minimal without shallowing the pavilion.
The trick is in the proper combination of table, crown height and pavilion depth. Even if a marquise is cut "perfectly" it will still have a bowtie.When a skilled cutter executes the right cutting combinations, bow-tie''s are not seen and you get a great looking marquise.
Girdle Area:
Very thin or extremely thin near the "points" is a no - no. On fancy shape diamonds, if the report says thin, you need to find out where the thin section is located. Thin girdles around the head of marquise shapes might lead to chipping and fracturing.
Very thick and extremely thick also require some scrutiny on fancy shapes and can affect overall size (too thick would be a stone cut with extra weight in the girdle).
Shopping by the Numbers:
A good general rule of thumb in searching for any diamond, particularly a fancy-cut stone is to not solely rely on searching out a stone solely based on the numbers. Two marquise stones which generate the same numbers can have dramatic differences in light return and visual performance.
With this said, one route to take in initially weeding out stones by evaluating the numbers is as follows:
A good reference can be found for fancy shapes at Dave Atlas’s website www.gemappraisers.com listed by clicking on the “AGA DIY Cut Grading” link and selecting marquise.
After initially looking at these charts, my advice is to get a sarin or megaScope reports on marquises that "look" good by the parameters set forth in these charts, which also have a solid grading certificate from one of the reputable labs like AGS, GIA, or HRD..etc.Get a good general idea of what you are looking for as far as color and clarity. Getting a vendor to supply you with this information might be a daunting task at first, but there are plenty of vendors who have access to this information and you should insist on being supplied with it in picking out possible stones.
The next step is to arrange to ''see'' these diamonds and determine how the numbers stack up to your eye. This will be the most important task in picking out your stone. Consumers have many different taste which vary from person to person.
The following chart was posted by Barry of Super-B-Cert in which he outlines guidelines in ensuring some of the most brilliant marquise stones:
Length to Width ratio: at least 1.8/1 (2:1 is optimal).
Table Range: 57% to 68%
Depth: 62% " 75%
Crown height:11% " 15.6%
Girdles: Medium to slightly thick
Be cautious with extremely thin to very thin girdles
as this may exacerbate chipping and fracturing.
Finding Length to Width Ratio: You would take the measured length of the stone in millimeters and width of the stone in millimeters, dividing the length by the width and that will give you the length to width ratio.
The following outline concerning ( length in mm and width in mm) for a marquise is described and directly quoted from RockDoc Bill Lieberum who is a leading edge appraiser and can be contacted at consumersgemlab.com.
“The measurements ( length in mm and width in mm) for a marquise is going to vary based on four basic factors.
1. Length to width ratio. There are long thin shaped marquises as well as short "stubby" one. The cutter fashions the stone based on retention of weight of the rough diamond crystal, and the removal of inclusions within it.
2. The crown height. There are steep crowns and shallow crowns and those that are "just right". The height or shallowness of the crown will have an effect on the length and width of the stone.
3. Girdle Thickness - The thickness of the girdle ( edge of the stone) also "adds weight" to the stone, and would "subtract" from its length to width ratio.
4. Pavilion Depth - This is an important area. 2/3''rds of the weight of a diamond is usually located in its belly. So the deeper the pavilion depth is the small the face up outline will appear. The cutter can fashion a deep stone that looks smaller face up which depending on HOW DEEP its cut, can detract from its appearance or he can cut a flat thin stone where the face up appearance looks larger, but usually this causes the stone to have an over brilliant, flat and dull appearance. Cutting too deep will make the "bowtie" look more predominant.”
Key points to Remember:
Symmetry grades in Fancies is not as important or critical as it is in rounds.
On fancy cuts the numbers ( proportions ) are not dependably predictable relevant to its quality of appearance and light return. For instance there are "dead stones" with great numbers, and great looking stones which fall outside the "suggested" parameters. There is no reliable consistency on what the numbers should be, rather stones which fall in certain parameters will most likely produce a more appealing diamond.
Fancy shapes depend greatly on the pleasing nature of their outline shape. A marquise can be pointy or fat until near the points. This makes a difference in how the marquise cut looks to your eye. There are certain aspects of cutting and artistry involved beyond length, width, depth and percentages.
Marquise cut diamonds are cheaper than rounds which are in higher demand and you can save 20% + on a marquise diamond which falls in the same weight range for the pricing of typical rounds. You can get more for your money, buying a marquise stone.
It is a good idea in getting the stone examined by a qualified appraiser who knows the nuances involved with cut grading a fancy.
Hope This Helps...
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