Friday, 3 December 2010

Brief History of Cut Diamonds

Diamonds, known for over 3000 years, were probably first found in India as loose stones associated with the sand and gravel of riverbeds (alluvial deposits). For centuries they were thought to posses magical powers, no doubt because of their hardness and luster, and were kept, uncut, as sacred objects or important treasures of state by the religious and political leaders of the day. Being regarded as talismans, it was thought that they would lose their powers if they were altered in any way.
It wasn't until the 11th century that diamonds were first worn, in their uncut form, as adornments. However, with the use of diamonds in jewelry, sometime in the 13th century it became known that a diamond's appearance could be enhanced by grinding and polishing [later by cleavage (below)] along the four octahedral faces (below) of the rough crystal. This was achieved by polishing with diamond dust at angles varying slightly from those of the original octahedral faces to form a point cut (below). (It had been discovered early on that the planes parallel to these faces are the hardest and can't be polished.) Point cuts were seen from the Middle Ages until the Renaissance period. 

The table was the first major facet to be fashioned on a diamond crystal. Thus, thetable-cut (below) diamond was formed by grinding down the top octahedral point to form a square facet using a recently discovered technique called bruting. This table facet was then finished off by polishing with diamond powder. (Bruting is the process where a diamond or diamond chip is used to wear away a portion of another diamond crystal. This method is still applied in modern cutting to form the rounded shapes of the girdles and pavilions of various shaped stones.) 

Later, table-cut diamonds were further modified by adding a smaller facet to the lower octahedral point to form a culet at the bottom of the stone. These culets were often large, as much as half the size of the table, and designed to reflect light and add brightness to the diamond. (We now know that the planes of the table and culet are oriented in one of the three cubic planes of the diamond rough, which are called the sawing directions, and are known to be the softest in the crystal.) 

With time, many of the older point-cut stones were converted to table cuts because of their popularity. Subsequently, table cuts themselves were further modified by adding eight narrow facets, one to each edge of the table and pavilion, in order to improve the brilliance of the stone.


A major advance in faceting came about with the introduction of the polishing wheel, or scaife, in the middle of the 14th century. This led the way for manufacturing brighter diamonds with increased facet pattern complexity. In this same era the rose cut(below) appeared. Its shape is basically flat and usually circular, with a faceted, domed top and plain bottom. This cut was well suited to the use of diamond fragments and the thinner forms of diamond rough called macles and flats. The major sources of this cut, which had many variations, were the diamond centers of Amsterdam and Antwerp, and were common until the early 1900's. 

By the mid-seventeenth century the old single cut (below) emerged. This design was formed by producing a more rounded overall shape with an octagonal-shaped table and eight facets on each the crown and pavilion. This cut eventually evolved into the brilliant cut with the complete rounding of the girdle and the application of additional facets to the crown and pavilion. Today round diamonds of less than 0.20ct. (used largely as accent stones in jewelry), called melee, are frequently cut as single cuts because smaller stones require fewer facets. 


The term "brilliant-cut" was coined at the end of the 17th century and was represented by several forms of faceted diamonds based on the shape of the commonly found octahedral form of the rough crystal. These cuts were round, rounded or cushion-shaped in girdle outline. During the early 18th century, Brazil, the new center of world diamond production, gave rise to the cushion-shaped old-mine cut (below), a forerunner of the modern brilliant cut having 33 crown and 25 pavilion facets, the same 58 facets as today's round brilliants. These cuts are still seen in some older estate pieces. 

With the 19th century came the rounded cuts like the old European cut (OEC, below) and the English round cut (not shown), both of which also have a total of 58 facets of the same type as today's round brilliants. Old-mine and old European cuts are deep-cut with small tables and relatively large culets, whereas the English round cut has a shallower crown and pavilion and larger table. Theses cuts are still commonly seen in estate jewelry of that era.



The early modern Tolkowsky brilliant cut (below) emerged with Marcel Tolkowsky's published thesis entitled, "Diamond Design: A Study of the Reflection and Refraction of Light in Diamond", in 1919. This was a theoretical work describing the best proportions of a round brilliant diamond which would provide a balanced return of light (brilliance) and dispersion. As a result, many cutters were led to fashion many of the larger, high quality goods in the range of these proportions. These proportions are also sometimes called the "American Ideal Cut", even though the work originated in Europe. Subsequently, the American Gem Society adapted proportional ranges for their "Ideal" (zero, 0, best) cut grade, based on this work and they are still used today. (For a detailed description of the meaning of what is an Ideal Cut round brilliant diamond, please read our Free Article on this subject.) 


Today's modern round brilliant (below) cut diamond, produced largely since World War II, differs in several ways from the Tolkowsky cut. The Tolkowsky brilliant had a larger culet, visible through the table, whereas today's round brilliant has either no culet, or a very small or small culet. Also, the table size range is larger in today's round cuts (about 53-57%, as a % of the stone's average diameter), but still include Tolkowsky's calculations which called for a 53% table. Finally, the lower girdle facets are now cut much deeper (about 75%) down the pavilion compared to earlier patterns, where they were cut to only about 1/3 of the pavilion depth. 



CUT IS KING!
Now that you have a little insight into the history of diamond cuts, remember that it is largely the quality of the cut, which releases the beauty of the diamond to your eyes. Thus, the most important guideline to remember when selecting any diamond is, "Find the stone with the best cut quality you can afford." In short, "CUT IS KING!", for it really doesn't matter if you have chosen a stone with D color and Flawless clarity, if it is not well proportioned, you will forever have a dull, lifeless looking diamond! On the other hand, if you select a diamond which appears colorless to your eye (usually D to I color) and whose inclusions you can't see with the naked eye (usually Fl to SI1 and sometimes SI2) and then go for the best cut quality you can afford, you will have a bright and lively diamond forever!
For the round brilliant, there are ranges of proportion and grades of finish (polish and symmetry) which are widely recognized as "Ideal" by the trade and are part of the grading system of the American Gem Society (AGS). These criteria can also be applied to diamonds graded by the Gemological Institute of America (GIA), which doesn't offer a cut grade in their report. These criteria require that GIA-graded diamonds have polish and symmetry grades which are "excellent", and that the proportions fall within the AGS Ideal (or zero) ranges as measured by a proportion analyzer called a Sarin instrument. It is important to make sure that you have this information before selecting a diamond.
Dutton's Diamonds specializes in Ideal cut AGS0 (sometimes erroneously called AGS triple zeros) and GIA Ex/Ex branded and unbranded round brilliant diamonds (many with Sarin reports). These diamonds are cut to superior proportions and finish, giving you the best in brilliancedispersion andscintillation. And as a final bonus, many also show the coveted Hearts & Arrows pattern, which is the mark of outstanding cut symmetry! 

Fancy Shapes



The round brilliant cut diamond is by far the most popular shape, and accounts for about 3 out of 4 diamonds purchased today. The modern ideal proportions for the round brilliant cut diamond (sometimes called the American Ideal Cut) arose from a mathematical thesis written by Marcel Tolkowsky and published in 1919 entitled, "Diamond Design: A Study of the Reflection and Refraction of Light in Diamond". Its 58-faceted design (33 crown and 25 pavilion facets) produces the greatest brilliance, dispersion and scintillation among all the major shapes.
However, there are several other shapes, called fancy shapes or fancy cuts, which with the exception of the emerald cut, are also brilliant cut or modifications thereof. They are frequently chosen as the center stones in rings and other jewelry (shown below in their face-up views). 

There are basically three types of cutting patterns, the brilliant cut, the step cut and the mixed cut (a combination of brilliant and step cuts). Sometimes diamonds with modified cuts are described both as to shape and faceting pattern in order to minimize confusion. For example, an oval shaped stone, which has a brilliant cut crown and a step cut pavilion, might be referred to as a "modified oval" or an "oval mixed cut".
Some of the fancy shapes are better suited for retaining the maximum weight of the more flat forms of diamond rough called macles and flats, and many are also cut from the less perfectly shaped octahedral and dodecahedral crystals. There are many other shapes (trilliant, bagette, etc.) and many branded cutting patterns which occupy specialized niches and more limited market positions, but we will not cover them here.
Factors important in selecting a fancy shaped diamond include all of the 4C's as they apply to the round shape. However, additional considerations come into play when considering fancy shapes such as the overall appearance of the outline of the girdle of the stone, the "bow tie" effect and the length-to-width ratio. Finally, one may ask, how does shape affect price? So here we will consider each shape separately and the factors which are important in how they impact beauty and price.
Currently there is no widely accepted "ideal" range of proportions for the fancy shaped diamonds. However, these may be developed in the future because it is known that the American Gem Society is working on this issue (see www.gemappraisers.com for details. This is probably the best classification of cut proportions in fancy shapes currently available.)
When looking at the general appearance of fancy cut diamonds, make sure that the stone is appealing to your eye and that it is bilaterally symmetrical. In other words, if you draw an imaginary line down its center length or across its width (excluding heart and pear in the latter case), one half of the stones should be shaped exactly as the other half. Also look at the shape of the pavilion, especially on emerald cuts, from all angles to make sure it isn't too deep and doesn't bulge excessively, an indication of extra weight retention and perhaps a reduction in light return (brilliance).
In many fancy shaped diamonds (marquise, pear, oval, emerald and heart shapes) the pavilion facets do not culminate at a point at the tip of the pavilion, but rather form an edge, called the "keel line". However, for grading purposes this is still referred to as the culet and should be judged accordingly.
Girdle width will vary between greater extremes on some fancy shapes compared to the round brilliant. These include the marquise, pear and heart, where the girdle tends to be thick or extremely thick at the tips of the stone and in the cleft of the heart-shaped cut. Also, the princess cut, which has square corners, may have an extremely thin girdle in these areas. These situations are frequently encountered with fancy shapes, and attention needs to be paid to the potential problems of excessive weight vs. danger of cracking or chipping in diamonds with extremely thick or extremely thin girdles, respectively.
The bow tie effect, observed with the naked eye, is frequently found in marquise, oval, pear and some heart- shaped diamonds, and is considered to be a negative factor if prominent. It arises from the variations in the pavilion facet angles required in cutting stones which are longer than they are wide. The bow tie looks like two dark triangular shapes joined at the point in the center of the stone (below), and is thought to be the result of light leaking from the pavilion. Caused sometimes by an overly deep pavilion, in a well-cut diamond its appearance should be minimal or absent and certainly not a distraction. 

Table measurements used in calculating table size are made at the point of their greatest width, and for the pear and heart shape this is not in the center of the stone, but is at the greatest overall width of the stone. This is the same line along which the width of the diamond should be measured in calculating the length-to-width ratio. For the heart shape, the length of the stone is measured in a vertical line, centered over the cleft, as the distance from the top of the shoulders to the tip.
SHAPES
ROUND - Information for the round brilliant has been described on this site in detail under the topics of the 4C's. The round brilliant diamond, being by far the most popular diamond shape is, because of market forces, the most expensive. Rounds make up the vast majority of diamonds found in engagement rings, and are also popular as stud earrings and pendants. You just can't go wrong with a round!
MARQUISE - The marquise (pronounced "mar-KEYS", not "mar-KEY") is usually cut as an adaptation of the 58-facet standard brilliant, with the crown having 33 facets and the pavilion 25 facets of the same type as the round brilliant. However, the pavilion can be cut with either 4, 6 or 8 pavilion mains facets, depending upon the stone's girdle outline. These modifications are also seen in the pavilion cuts for the pear, oval and heart shaped diamonds.
The crown cut is also sometimes modified in the marquise to form what is called a "French tip", where the bezel facet at the point of the stone is eliminated. As an example for comparison, below is a diagram showing what an imaginary hybrid-cut marquise would look like where the upper half of the stone is cut as a French tip and the lower half is cut as a standard brilliant. Note how the elimination of the bezel facet at the point of the stone requires that the adjoining bezel facets become "stretched" to accommodate the space left. French tips are also sometimes cut in pear and heart shaped diamonds. 

The length-to-width ratio is important to a stone's appearance, and for the marquise shape the preferred range is 1.75-2.25: 1.00. Marquise diamonds frequently show a bow tie, so try to find a stone in which this is minimal or absent. This shape of diamond in a ring accentuates the length of the fingers.
As a % of the diamond's width, the better cut marquise will have table % in the range of 53-63% and total depth % (crown+girdle+pavilion) of about 58-65%.
The cost of a 1ct., D, IF marquise is about 20% less than that of an identical round diamond. For a 1ct., G, VS2 stone, the marquise cut is only about 7% cheaper than the same round diamond.
PEAR - The pear shape, like the marquise, usually has the 58 facet brilliant pattern, but can also be cut with different numbers of pavilion mains of 8,7,6 or 4 facets.
In a pear, look for a well-shaped head and even shoulders with an optimal length-to-width range of 1.50-1.75:1.00. This shape in a ring will make the fingers appear longer. Pear-shaped diamonds work equally well as pendants and are exceptional as drop earrings.
Ranges for the well cut pears for table % and total depth % are about 53-63% and 58-65%, respectively.
The relative cost of a 1ct., D, IF pear shaped diamond is roughly 25% less than an identical round stone, but a 1ct., G, VS2 pear is only 20% less than the cost of an identical round.
OVAL - The oval, as with the above examples, is seen most frequently cut in the standard 58 facet brilliant pattern, but again can have a varying number of pavilion mains facets ranging from 4, 6 or 8.
For ovals, look for even, well-rounded ends with a full body having an optimal length-to-width range of 1.33-1.66: 1.00. This shape of stone in a ring accents finger length, and also works nicely as stud earrings.
Higher cut quality ovals, as with the marquise and pear, have table %'s of about 53- 63% and total depth %'s of 58-65%.
The relative cost of an oval diamond of 1ct., D color and IF clarity is roughly 25% less than an identical round stone, but a 1ct., G, VS2 oval is only 20% less than the cost of an identical round.
RADIANT - The radiant cut is a patented name and cut called a cut-cornered, square/rectangular (depending on the overall shape) modified brilliant on GIA grading reports. It has a total of 70 facets, there being 25 crown, 8 girdle and 37 pavilion facets. The truncated corners may aid in avoiding or minimizing possible chipping problems posed by extremely thin girdle widths in these areas of the stone.
Generally, a ring with a square cut radiant tends to shorten the appearance of the longer fingered hand.
Radiants of higher cut quality will have table %'s of about 59-69% and total depth %'s ranging from about 59-69%. Deep pavilions are often seen on many radiants and princess cuts and contribute to the increased total depth % seen in these stones. However, this extra depth is often necessary to bring out the maximum brilliance in the stone.
The comparative cost of a 1ct., D, IF radiant diamond is roughly 33% less than an identical round stone, but a 1ct., G, VS2 radiant is only about 20% less than the cost of an identical round.
PRINCESS - The princess cut is called a square/rectangular modified brilliant in GIA grading reports. It may have either 50 facets (21 crown, 4 girdle, 25 pavilion) or 58 facets (21 crown, 4 girdle, 33 pavilion), depending on how the pavilion is cut.
This cut of diamond is frequently a square shape and therefore shortens the appearance of the longer fingered hand. The princess cut has sharp, squared-off corners, and if the girdle is extremely thin in these areas, chipping or cracking may occur more easily.
Princess shapes of high cut quality usually have a table % in the range of roughly 60-75% and a total depth % of about 65-80%.
As with the radiant, the cost of a 1ct., D, IF princess diamond is roughly 33% less than that of an identical round stone, but a 1ct., G, VS2 princess is only about 20% less than the cost of an identical round.
EMERALD - The emerald cut is not a brilliant cut, but is called a step cut. Step cuts are comprised of larger, planar facets which act like mirrors. The emerald cut has 58 facets, with 25 crown, 8 girdle and 25 pavilion. Because of the angle, size and shape of the facets, the emerald cut shows less brilliance and fire (dispersion) than the other brilliant and modified brilliant cut diamonds. However, the emerald cut stone reveals a classic and aristocratic elegance and beauty not seen in other cuts.
Because of the open and large, plate-like nature of the facets, it is highly recommended that you consider staying at higher color (D-G) and clarity (IF-VS2) grades than you might with a brilliant cut stone because they are more likely to become visible at lower grades. Also, check to make sure that all the facet edges appear parallel in the face-up position. If they aren't, it can be pretty obvious at times.
The emerald cut offers a touch of regal elegance as the center stone in a ring, and the most attractive proportions are a length-to-width ratio range of 1.50-1.75:1.00. However, some prefer a more square look with a ratio in the range of 1.30:1.00. Obviously, the more square the shape, the more it compliments the longer-fingered hand, and the more rectangular, the better suited it is to the shorter-fingered hand.
The better emerald cut diamonds, like radiants, will have table %'s of about 59-69% and total depth %'s ranging from about 59-69%.
Like both the radiant and princess, the cost of a 1ct., D, IF emerald cut diamond is roughly 33% less than that of an identical round stone, but a 1ct., G, VS2 emerald is only about 20% less than the cost of an identical round.
HEART - The heart shape is a brilliant cut, which can also be modified so that the number of pavilion mains may be 6, 7 or 8.
In a heart cut it is important to look for a perfectly symmetrical appearance where the lobes (top arches) are of even height and breadth, and the overall shape pleasing.
The better cut heart shapes will have a length-to-width ratio of just about 1.00:1.00, with a little variation from about 0.98:1.00 to 1.02:1.00.
This shape is seen frequently in pendants, but is suitable for most any purpose.
The well-cut heart shaped diamonds will have a table % in the 53-63% range, and a total depth of about 58-65%.
Roughly comparable with the pear and oval shapes, the relative cost of a 1ct., D, IF, heart shaped diamond is approximately 25% less than an identical round stone, but a 1ct., G, VS heart is only about 20% less than the cost of an identical round diamond.

Tuesday, 30 November 2010

How To Know If A Diamond Is Fake Or Real

Certified Diamond (Round, Very Good cut, 1.11 carats, F color, SI2 clarity)         A diamond is a girl's best friend! It is a beauty and unique nature makes it easy to admire. Diamond purchasing is a great task and an exciting pleasure. There are various types of diamonds so when buying real diamonds, one should learn about fake diamonds so that you will be able to distinguish between the fake vs. real diamond. Nowadays the best fake diamond is in great demand. Here are some of the simple solutions or the methods that will enable you to find out the difference between the fake vs. real diamond. The best way to know about the precious diamond is to acquire knowledge from a diamond professional. If possible take the diamond along with you to the shop and get all the details from the jeweler. The best fake diamond looks so similar to the real diamond that even a professional diamond jeweler may get confused and may have hard time to finding out whether it is a fake or the real diamond. In case you are not satisfied with the views regarding the real diamond from the professional, here is a way to find out which is a real diamond and which is a fake diamond.

The first method is to check the diamond with the help of diamond tester as it will help you to differentiate between real diamond and best fake diamond. It is an electronic tester that can check all the diamonds except the moissanite stone for which the diamond tester is not reliable. The best fake diamond is the cubic zirconia and the weight of this diamond is around 50% more than a real diamond of the same size and shape. This weighing test also can find out the difference between fake vs. real diamond.

Another method for checking the best fake diamond is the transparency test in which the diamond is placed up side down on the news paper and if the written matter from the newspaper is legible then be sure that the diamond is not the real one and it can be a best fake diamond. One of the disadvantages of this method is that some of the stones may appear to be a real diamond due its fine cutting. In this case, one needs to be sure about the cuttingmethods of the stones. This method is very common and enables you to find the real diamond from the best fake diamond.

The third method that helps you to differentiate between fake vs. real diamond is the fog test. Hold the stone or the diamond and blow some air from your mouth on to the stone, if the fog appears on the stone and stays there for next few seconds then it shows that the stone is a best fake diamond because in case of a real diamond, the heat disappears instantly. The oily layers and dirt on the stone might create some problems to differentiate fake vs. real diamond. Thus, before carrying out a test for best fake diamond, clean its surface properly.

The ultra violet test is another method that will enable you to find out the real diamond from the best fake diamond. The real diamond projects blue color light if put under the ultra violet light or the black color. There are two options, if the blue light does not appear, it can be best fake diamond or can be a high quality diamond.

All of the above tests can satisfy all the test conditions to differentiate between a best fake diamond and the real diamond.

Monday, 29 November 2010

new selection dimaond

diamond number one

Blue Diamond


blue diamond jpg
blue diamond jpg The Blue Diamond The blue diamond gets its color from the boron in its composition They are mined in Australia and South Africa and along with the red diamond are the most rare and valuable of the colored
blue diamond 48 jpg
blue diamond 48 jpg OK so this isn t really anything in depth nor is it probably surprising but for alchemists I find specially at the minute with all the socketed T7 and T7 5 gear that we re officially
diamond084blue240 JPG

rare blue diamond jpg
rare blue diamond jpg Privacy Policy Disclaimer of Warrenties and Visitor Code of Conduct © 2009 Via Video All rights reserved
diamond ring C150 jpg

Power/Success Natural

Zorbitz Inc. - Power/Success Natural - Karmalogy Beads