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Diamond Grading Report: Why you need it and what it is telling you.

A Diamond Grading Report issued by an Independent Gemological Laboratory, tells you that the Diamond has been examined by experienced Diamond Graders, using various gemological instruments, and contains the characteristics as stated in the Certificate.

The reason it is important to have a Diamond evaluated by an independent Laboratory is that minute, invisible to the naked-eye, characteristics of a Diamond can have a major influence on the price. Therefore, if not for a great deal of scrutiny on the part of the buyer, it is easy to mistake and purchase a Diamond of lower value, believing it to be of higher value.

I strongly recommend that you do not buy any diamond without a Diamond Certificate. GIA is the foremost Laboratory in the world, though there are other reputable labs out there. However, not all labs are equal in their grading stringency, accuracy, and consistency.

If you found a Diamond you like, and it is not certified there is nothing wrong with asking your Jeweler to send it to a reputable independent Gemological Laboratory for certification. If your Jeweler has a problem with that, take a few steps back and ask yourself many more questions! This request is a standard practice in the Diamond Industry.

What's in a Diamond Lab name?

The number one most important item to look for on a Diamond Certificate is the name of the laboratory! If you never heard of the Laboratory, don't feel shy about giving them a call to check them out. Also, if the laboratory is an independently owned franchise and the certificate you were given is not local, you may want to call up the lab, either the local one or the one that issued the certificate, and ask them by which standards they grade their Diamonds. Find out if they honour the grades given out by other branches.

GIA is the foremost grading laboratory in the world both for their excellence in diamond and gemstone grading as well as for their comprehensive research and educational programs to both the trade and consumers.

GIA cert.jpg
Actual GIA Grading Report:

parts.jpg
Basic Parts of a Round Brilliant Diamond.

Let's go over this report and examine the information it gives you:

Every lab has a certificate (or " report") number, which uniquely identifies a Diamond. The Lab keeps an internal copy of everything which you see on the certificate, plus some additional information for their files. If you call up the Lab and give them the certificate number, they can even reissue a certificate if you lost it. This report number is found in the upper left-hand margin and appears vertically. The Cert number for the GIA report shown here is: 11510402.

Diamond Shape: Self explanatory.

Measurements: Measurements of the Diamond's diameter:
"minimum - maximum x depth" are calculated to the hundredth of a millimeter by a Leveridge Guage or a micrometer.

Weight: Diamonds are weighed to the thousandth of a carat with a digital measuring device. On the certificate, weight is rounded to the hundredth of a carat. Diamonds are always measured in carat weight. One carat is the equivalent of 1/5 of a gram. Additionally, there are "100" points in a carat, so that a .50 "point" diamond would be described as a half-carat.

In general, the pricing structure for polished diamonds is directly related to the pricing structure for the diamonds in their rough state. Because there is a scarcity of large diamond rough, the price for these diamonds after polishing will be higher per carat. As you get larger in carat weight there will be an incremental jump in price even between two diamonds of same color and clarity. These plateaus are found approximately every .10-.15 points. Category examples are: .50-.59, .60-.69, .80-.89, .90-.99 carat, etc.

Proportions: Depth Percentage and Table Percentage are measured.
Depth percent refers to the percent of the depth of the Diamond, table to culet, relative to the width of the stone.
The Table of a Diamond refers to its largest facet, the main part of the Diamond you look at when the stone is face-up.
Table percent refers to the table size as a percentage of the Diamond's average width.

These ratios in conjunction with the Millimeter measurements indicate how "well" the Diamond has been cut.

Girdle: The Girdle of a Diamond is the dividing line between the crown, or top part of the stone and the pavillion, or bottom part of the stone. Girdle thickness can be very thin in part of a stone and very thick in another part. That is why it is expressed as a range. The girdle can also be faceted, or not. A faceted girdle usually improves the look of the stone, and involves having the cutter polish facets into the girdle.

Culet: If there is one, is the facet on the pointy bottom part of the Diamond. Its existence helps prevent chipping.

Finish of the Diamond, referred to as Polish and Symmetry:

Finish describes the polish of a Diamond and how symmetrical, or how evenly, the facets have been placed.
Polish refers to the quality of the polish on the facets. An excellent polish reflects the care taken by the Diamond cutter.
Symmetry refers to how precisely the facets are externally aligned to each other. All the facets should have more or less the same shape and size.

Clarity Grade:

Clarity ranges from the best grade of IF, down through VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2 until I3. Clarity is a reflection of the number, size, placement and nature of inclusions and/or surface irregularities on the Diamond. The experienced Diamond Grader examines the Diamond with the aid of a Stereo Microscope, which aids in identifying the nature of an inclusion, or finding pinpoints (very, very tiny crystals inside the Diamond). However, the actual grade is based only on what is visible under a 10X Loupe.

Color:

Color ranges from the best grade of D, down to Z. After Z are Fancy Colors. Color grade is determined by examining the Diamond next to a master set of color comparison stones, under special lighting.

colorgrad.gif


Fluorescence:

Fluorescence refers to a Diamond's reaction to long wave ultraviolet radiation. Fluorescence or blue diamonds is a hotly debated topic with much erroneous information being disseminated to consumers.

Read this link on our Blog for more detailed and accurate information on blue diamonds. Blue Diamonds

The Diamond Plot:

The Diamond Plot is a graphical representation of the imperfections of the Diamond. Each Diamond is as unique as a fingerprint. By plotting its characteristics, and combining this with the physical measurements of a Diamond, a Lab can uniquely identify each stone. This plot helps the Grader in the even that a customer returns to the Lab and requests a verification that the Diamond presented with a certificate refers to the same Diamond described in the Certificate.
Internal characteristics are plotted in red, and external characteristics are plotted in green.

Comments:

Comments are used to describe characteristics not discussed elsewhere on the certificate, or to mention items not plotted. For example, "minor details of polish are not shown" is a common comment. "Crown angles over 35 degrees", or Crown angles under 30 degrees" are other comments pertaining to Cut that may also appear.


Posted by Barry Gutwein on December 29, 2004 4:03 PM in Diamond Basics | Comments (72)

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This is getting a bit more subjective, but I much prefer the Zune Marketplace. The interface is colorful, has more flair, and some cool features like 'Mixview' that let you quickly see related albums, songs, or other users related to what you're listening to. Clicking on one of those will center on that item, and another set of "neighbors" will come into view, allowing you to navigate around exploring by similar artists, songs, or users. Speaking of users, the Zune "Social" is also great fun, letting you find others with shared tastes and becoming friends with them. You then can listen to a playlist created based on an amalgamation of what all your friends are listening to, which is also enjoyable. Those concerned with privacy will be relieved to know you can prevent the public from seeing your personal listening habits if you so choose.

The new Zune browser is surprisingly good, but not as good as the iPod's. It works well, but isn't as fast as Safari, and has a clunkier interface. If you occasionally plan on using the web browser that's not an issue, but if you're planning to browse the web alot from your PMP then the iPod's larger screen and better browser may be important.

Sorry for the huge review, but I'm really loving the new Zune, and hope this, as well as the excellent reviews some other people have written, will help you decide if it's the right choice for you.

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Sorry for the huge review, but I'm really loving the new Zune, and hope this, as well as the excellent reviews some other people have written, will help you decide if it's the right choice for you.

The Zune concentrates on being a Portable Media Player. Not a web browser. Not a game machine. Maybe in the future it'll do even better in those areas, but for now it's a fantastic way to organize and listen to your music and videos, and is without peer in that regard. The iPod's strengths are its web browsing and apps. If those sound more compelling, perhaps it is your best choice.

Between me and my husband we've owned more MP3 players over the years than I can count, including Sansas, iRivers, iPods (classic & touch), the Ibiza Rhapsody, etc. But, the last few years I've settled down to one line of players. Why? Because I was happy to discover how well-designed and fun to use the underappreciated (and widely mocked) Zunes are.

The new Zune browser is surprisingly good, but not as good as the iPod's. It works well, but isn't as fast as Safari, and has a clunkier interface. If you occasionally plan on using the web browser that's not an issue, but if you're planning to browse the web alot from your PMP then the iPod's larger screen and better browser may be important.

Between me and my husband we've owned more MP3 players over the years than I can count, including Sansas, iRivers, iPods (classic & touch), the Ibiza Rhapsody, etc. But, the last few years I've settled down to one line of players. Why? Because I was happy to discover how well-designed and fun to use the underappreciated (and widely mocked) Zunes are.

Zune and iPod: Most people compare the Zune to the Touch, but after seeing how slim and surprisingly small and light it is, I consider it to be a rather unique hybrid that combines qualities of both the Touch and the Nano. It's very colorful and lovely OLED screen is slightly smaller than the touch screen, but the player itself feels quite a bit smaller and lighter. It weighs about 2/3 as much, and is noticeably smaller in width and height, while being just a hair thicker.

Hands down, Apple's app store wins by a mile. It's a huge selection of all sorts of apps vs a rather sad selection of a handful for Zune. Microsoft has plans, especially in the realm of games, but I'm not sure I'd want to bet on the future if this aspect is important to you. The iPod is a much better choice in that case.

If you're still on the fence: grab your favorite earphones, head down to a Best Buy and ask to plug them into a Zune then an iPod and see which one sounds better to you, and which interface makes you smile more. Then you'll know which is right for you.

This is getting a bit more subjective, but I much prefer the Zune Marketplace. The interface is colorful, has more flair, and some cool features like 'Mixview' that let you quickly see related albums, songs, or other users related to what you're listening to. Clicking on one of those will center on that item, and another set of "neighbors" will come into view, allowing you to navigate around exploring by similar artists, songs, or users. Speaking of users, the Zune "Social" is also great fun, letting you find others with shared tastes and becoming friends with them. You then can listen to a playlist created based on an amalgamation of what all your friends are listening to, which is also enjoyable. Those concerned with privacy will be relieved to know you can prevent the public from seeing your personal listening habits if you so choose.

This is getting a bit more subjective, but I much prefer the Zune Marketplace. The interface is colorful, has more flair, and some cool features like 'Mixview' that let you quickly see related albums, songs, or other users related to what you're listening to. Clicking on one of those will center on that item, and another set of "neighbors" will come into view, allowing you to navigate around exploring by similar artists, songs, or users. Speaking of users, the Zune "Social" is also great fun, letting you find others with shared tastes and becoming friends with them. You then can listen to a playlist created based on an amalgamation of what all your friends are listening to, which is also enjoyable. Those concerned with privacy will be relieved to know you can prevent the public from seeing your personal listening habits if you so choose.

Zune and iPod: Most people compare the Zune to the Touch, but after seeing how slim and surprisingly small and light it is, I consider it to be a rather unique hybrid that combines qualities of both the Touch and the Nano. It's very colorful and lovely OLED screen is slightly smaller than the touch screen, but the player itself feels quite a bit smaller and lighter. It weighs about 2/3 as much, and is noticeably smaller in width and height, while being just a hair thicker.

If you're still on the fence: grab your favorite earphones, head down to a Best Buy and ask to plug them into a Zune then an iPod and see which one sounds better to you, and which interface makes you smile more. Then you'll know which is right for you.

I'll gear this review to 2 types of people: current Zune owners who are considering an upgrade, and people trying to decide between a Zune and an iPod. (There are other players worth considering out there, like the Sony Walkman X, but I hope this gives you enough info to make an informed decision of the Zune vs players other than the iPod line as well.)

Hands down, Apple's app store wins by a mile. It's a huge selection of all sorts of apps vs a rather sad selection of a handful for Zune. Microsoft has plans, especially in the realm of games, but I'm not sure I'd want to bet on the future if this aspect is important to you. The iPod is a much better choice in that case.

The Zune concentrates on being a Portable Media Player. Not a web browser. Not a game machine. Maybe in the future it'll do even better in those areas, but for now it's a fantastic way to organize and listen to your music and videos, and is without peer in that regard. The iPod's strengths are its web browsing and apps. If those sound more compelling, perhaps it is your best choice.

If you're still on the fence: grab your favorite earphones, head down to a Best Buy and ask to plug them into a Zune then an iPod and see which one sounds better to you, and which interface makes you smile more. Then you'll know which is right for you.

Apple now has Rhapsody as an app, which is a great start, but it is currently hampered by the inability to store locally on your iPod, and has a dismal 64kbps bit rate. If this changes, then it will somewhat negate this advantage for the Zune, but the 10 songs per month will still be a big plus in Zune Pass' favor.

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