Diamond clarity is the diamond quality associated with the presence and visual appearance of internal diamond characteristics called inclusions , and surface defects, called defects . Clarity is one of four diamond gradations, the other is carat, color, and piece.
Inclusion is solids, liquids, or gases trapped in minerals as they form. They may be crystals of foreign material or even other diamond crystals, or may have produced structural imperfections, such as tiny cracks that make diamonds appear whitish or turbid. The number, size, color, relative location, orientation, and visibility of all inclusions can affect the relative clarity of diamonds. The degree of clarity is given based on the overall appearance of the stone under ten times of magnification.
Most inclusions present in gem-quality diamonds do not affect diamond performance or structural integrity and are invisible to the naked eye. However, large clouds can affect the ability of diamonds to transmit and disseminate light. Large cracks that close or break the surface can reduce the diamond resistance to the fracture.
Diamonds with higher clarity values ​​are more appreciated, with very rare "Flawless" graded diamonds at the highest price. Inclusion or minor defects are useful, as they can be used as unique identification marks analogous to fingerprints. In addition, as synthetic diamond technology improves and distinguishes between natural and synthetic diamonds becoming more difficult, inclusions or defects can be used as evidence of natural origin.
Video Diamond clarity
Inklusi dan blemishes
There are several types of inclusions and defects, which affect the clarity of diamonds to different levels. Features resulting from diamond elevation procedures, such as laser lines, are also considered inclusions or defects.
Inclusion
- Cloud
- Fur
- Crystals or minerals included
- Loop
- Cavity
- Cleavage
- Apply
- Internal grid
- Find
- Laser line
- Twinning Wisp
- Grain Center
- Laser drill hole
- Loop
- Needles
The diamond industry uses the term "internal characteristics" instead of "inclusion". For natural diamonds, the "internal characteristic" in diamonds is a growth crystal that delivers unique character diamonds and fingerprints. When diamonds are graded, they are enlarged with 10x power.
Blemishes
- Polish line
- Grain boundaries
- Naturals
- Scratches
- Nicks
- Holes
- Chips
- Rest
- Dark spots
- Light spots
- Abrasion
Maps Diamond clarity
Clarity grading
Gemological Institute of America scoring system
History
In 1952, Richard T. Liddicoat, along with Marquis Person, Joe Phillips, Robert Crowningshield and Bert Krashes began work on a new diamond scoring system they called "diamond grade assessment and evaluation appraisal". In 1953, they released their new system that assessed three aspects of diamond; make, color and clarity. They took the terminology used in the industry at the time and refined the definition to produce a scale of clarity that can be judged consistently by diamonds. The system at that time contains nine values: Flawless, VVS 1 , VVS 2 , VS 1 , VS 2 , SI 1 , SI 2 , I 1 , and I 2 . The 'I' value of class I 1 , and I 2 originally stood for "Not Perfect".
During the 1970s, two changes were made to the system. First, Internally Flawless grade is added, as the GIA realizes that many diamonds are cut aggressively to remove surface stains, thereby reducing the quality of the "make" of the diamond. The Internally Flawless class gives the diamond producer the option to leave a stain on the rock surface, and reach a value higher than VVS 1 . The second change made on the scoring system is the introduction of class I 3 . This change is done in response to more diamonds with a very low level of clarity.
The last change to the clarity assessment system took place in the 1990s when the term "imperfect" was changed to "include".
The modern GIA scoring system
The GIA diamond scoring scale is divided into six categories and eleven values. The categories and values ​​of clarity are:
- Flawless category (FL) diamonds have no inclusions or defects that look below 10x magnification.
- Internally flawless category (IF) diamond has no inclusion seen below 10x magnification, just a small stain on the diamond surface. The Category
- Very, Very Covered category (VVS) has a minute inclusion that is difficult for a skilled class kid to see under 10x magnification. The VVS category is divided into two classes; VVS1 shows a higher clarity level than VVS2. Pinpoint and needle set the value in VVS. The category
- Very Covered category (VS) has a small inclusion that is difficult to rather easy for a trained class student to see when viewed under 10x magnification. Category VS is divided into two classes; VS1 shows a higher level of clarity than VS2. Usually inclusion in VS diamonds is not visible without enlargement; however, some VS2 inclusions may still be visible. An example is on a large emerald diamond piece that has a small inclusion beneath the corner of the table. The
- Little Included (SI) diamond has a clear, easy inclusion very easy for a trained class student to see when seen under 10x magnification. SI categories are divided into two classes; SI1 shows a higher clarity than SI2. It may or may not be visible to the naked eye. The
- Included category (I) diamond has a clear inclusion that is clearly visible to a trained class student under 10x enlargement. Including diamonds have inclusions that are usually seen without enlargement or have inclusions that threaten the durability of the stone. Category I is divided into three classes; I1 shows a higher clarity than I2, which in turn is higher than I3. Inclusion in diamonds is often seen by the naked eye. I2 inclusions are easy to see, while diamond I3 has great inclusions and is very easy to see which usually affects the brilliance of diamonds, as well as has an inclusion that often threatens diamond structures.
GIA clarity assessment procedure
The GIA clarity assessment was performed under 10x magnification with darkfield illumination. The GIA laboratory uses standard stereo binocular microscope equipment that can zoom into higher magnification. This microscope is equipped with darkfield illumination, as well as an ultraviolet filtered overhead lamp. When the assessment is done using a 10x magnifying glass, darkfield illumination is more difficult to achieve. The class should use the light source in such a way that the base of the stone is lit from the side, and the stone crown is protected from light.
After completely cleaning the diamonds, the diamonds were taken with tweezers on a corset-to-corset belt. The class boy sees the diamond for the first time through the table, studying the stone culet area for inclusion. The diamond is then arranged and picked up with tweezers on the table-to-cocket handle. In this position, diamonds can be studied from the side of the pavilion, and the crown side, examining the diamonds through each facet for inclusion. Once a diamond sector has been thoroughly inspected, the grader spins the diamond in the brace, so that the neighboring sector can be checked. The classroom uses darkfield lighting to reveal characteristics, and alternates to reflect, overhead lighting to ascertain whether a characteristic is in a rock, on a stone's surface, or both. If the grader uses a stereo microscope, he can zoom in to higher magnification to make a closer observation of an inclusion, but then return to 10x magnification to make an impact assessment at the level of clarity.
If a binocular stereo microscope has been used, the final judgment using a 10x magnifier is performed before the final judgment is made on the clarity of the stone. The first grader decides the category of diamond clarity: none (FL, or IF for defects), minute (VVS), minor (VS), visible (SI), or clear (I). Decisions are then made at the diamond level.
Grading system by another organization
The clarity assessment system developed by GIA has been used throughout the industry as well as by other diamond grading institutions including the American Gemological Society (AGS), and the International Gemological Institute (IGI). There are other smaller laboratories that use the GIA system as well. These scoring bodies base their clarity on the inclusion characteristics seen by a trained professional when diamonds are seen from above under 10x magnification.
World Jewelery Confederation
World Jewelery Confederation developed International Clarity Scale to assess diamonds. The scale of this clarity reflects the scale of the GIA assessment, except that the nomenclature varies. The system specifies the value of this clarity; Very small inclusion (VS1 and VS2), Small inclusions (SI1 and SI2), Pique (P1, P2, and P3).
Clarity grading by WJC standard is by examination using 10x achromatic, aplanatic loupe in normal light.
American Gem Society
The American Society Gem values ​​the clarity on a number scale between 0 and 10. The number of these numbers correlates almost exactly with the GIA system, but with some differences. Perfect and flawed values ​​(0) are grouped together with a notation that defines whether the stone is free from external defects, the VVS to SI values ​​are numbered 1 to 6, and then there are four classes 7 to 10 for the categories included.
Clarity grading by AGS standards requires checks using a binocular stereo microscope equipped with adjustable zoom adjustment and darkfield illumination.
Diamond Council International
IDC or International Diamond Council uses standards very similar to CIBJO. IDC clean magnifier stones with external defects have notations made on the assessment report. IDC clarity grading is by examination using 10x achromatic, aplanatic loupe in normal light.
European Gemological Laboratory
The European Gemology Laboratory (EGL) introduced SI3 as a level of clarity. While intended as a range for inserting SI2/I1 boundary stone, it is now commonly used to mean "clean eye" I1, that is, having inclusions that are not clearly visible to the naked eye.
Consideration of clarity considerations
All values ​​reflect the appearance to an experienced class when viewed from above at 10x magnification, although magnification and higher view from another angle are used during the appraisal process. Grade students study diamonds for internal characteristics and assess them on the basis of five factors of clarity: size, number, position, nature, and color or relief. The value of clarity is judged on the basis of the most visible inclusion, called "setting level settings". Less significant inclusions are ignored for the purpose of assigning value; However, they may still be plotted into a diamond plot chart.
Explanations of accurate clarity levels such as other assessment steps should be performed with a "loose" diamond, ie not set to any installation. Inclusion is often difficult to see from the crown side of the diamond, and may be hidden by the arrangement.
Size
The first clarity factor to be assessed is the measure of the characteristics of clarity. Larger characteristics are usually more visible under enlargement, thus placing diamonds to a lower level of clarity.
Numbers
The second clarity factor assessed is the number of clarity characteristics. Generally, the more characteristics, the lower the level of clarity. This assessment is made by assessing how ready they can be seen, not by the number of actual characteristics.
Position
The third clarity factor assessed is the characteristic position. When direct inclusion under the diamond table is most visible. Inclusion under the table and positioned close to the pavilion facet will reflect several times around the rock, giving this type of inclusion the name "reflector". Reflector is considered as if each reflection is an inclusion (although in plotting the diamond it is only plotted once). For this reason, reflectors have a greater impact on the level of clarity. Inclusion becomes less noticeable when they are positioned under a crown facade, or near a stone corset. This inclusion may be more easily seen from the side of the diamond pavilion than from the crown side of the diamond.
In addition, the positions of large feathers, knots and including crystals are positioned where they extend to the corset or the stone crown affecting the level of clarity. Diamonds worn in jewelry will usually withstand damage, but the inclusion of these properties and in this position may pose a risk for further elongation of the breaks in diamond structures. The inclusions assessed to cause at least moderate risk of breaking into stones are assessed in the Included category.
Nature
The fourth clarity factor assessed is the characteristic trait. The properties of the properties determine whether it is internal (elongated to rock) or external (confined to the rock surface). Internal characteristics automatically exclude diamonds from the Flawless , and Internal Flawless categories. External characteristics exclude diamonds from the Flawless category.
The internal characteristics of diamonds can be classified as (n): bruises, cavities, pieces, cleavage, clouds, crystals, feathers, grain centers, natural indents, internal grating, knots, laser drill holes, needles, pinpoints, or twin blobs.
The external characteristics of diamonds can be classified as (n): abrasion, natural, nick, pit, polish lines, paint marks, scratches, lattice surfaces, or additional facets.
Nature will also determine whether inclusion poses a risk to the stone. The inclusions that may cause breaks in the crystal structure (including crystals, feathers, knots, and cleavage) may, depending on its position, lead to a moderate level of risk for further deterioration.
Color or relief
The fifth clarity factor assessed is the color and completeness of the clarity characteristics. The contrasting characteristics with the surrounding diamonds are said to have "help". The extent to which this color and relief is seen affects the level of diamond clarity. Colored inclusions always show contrast and are easier to see. An exception is the black pinpoint attachment, which is often more difficult to see than the white pinpoint.
Rarities and values ​​
Diamonds are becoming increasingly scarce when considering gradations of higher clarity. Only about 20% of all mined diamonds have a high enough clarity rating for diamonds to be considered appropriate for use as gems; The other 80% is degraded into industrial usage. Of the top 20%, most contain inclusions or inclusions visible to the naked eye after strict examination. Those who do not have the inclusions seen when gems are examined about 6 inches from the naked eye are known as "eye-clean", although visible inclusions can sometimes be hidden under the arrangements in a piece of jewelry. The most expensive diamond diamonds fall in the VS and SI levels with FL, IF, and even VVS stones that provide significant premiums. FL and IF stones are sometimes referred to as "museum quality" or "investment level" to indicate their scarcity even though the term "investment grade" is misleading because diamond has historically been an illiquid and questionable storefront.
Since many rare diamond purchases (eg engagement rings), there is a level of concern by end consumers who have to pay a large premium for the difference in clarity levels that are important to the certificate or diamond industry, but not to the buyer's community, who generally can not be aware of the difference with the naked eye.
Improved clarity
Laser "drilling" involves the use of lasers to burn holes into colored inclusions, followed by acid leaching to remove dyes. The value of clarity is value after treatment. Treatment is considered permanent.
Clarity can also be "enhanced" by filling a fracture such as car glass cracks can be treated. Such diamonds are sometimes called "diamond filled fractions". Trusted vendors should disclose this charging and a reputable charging company using a filling agent that shows flashes of color, usually orange or pink, when viewed closely. There are significant price discounts for diamonds that are filled with fractures. The GIA will not assess diamonds that are full of fractures, partly because the treatments are not as permanent as the diamond itself. Leading companies often provide re-maintenance if heat causes damage to charging. The heat required to cause damage is that a torch is used to work on the setting, and it is important to inform anyone working on the arrangement if the diamond is full of fractures, so they can apply a cooling agent to the diamond and use a larger treatment. do it.
The GIA, as a matter of policy, does not rate diamonds that are perfected with clarity but will assess laser-fed diamonds as they consider the increase to be permanent. If the GIA report has the words "enhanced clarity" or "fracture filled", it must be a false report.
See also
- Diamond
- Diamond color
- Diamond Improvement
- Synthetic diamond
References
Source of the article : Wikipedia
0 Comments