Now that you know how important the proportions are in the diamond you're going to purchase, HOW ARE YOU GOING TO KNOW WHAT YOU'RE GOING TO GET???
What's even more difficult is that GIA, the most recognized lab in the industry does not give you pavilion depth, pavilion angles, crown height or crown angles. When it comes to the numbers they only give you table percentage and total depth. What does this tell you? Very little. You can have a diamond that is GIA certified, D color, Internally flawless and be the dullest looking thing you ever laid eyes on. Can you imagine going out and buying a D-F color diamond with a VVS or VS clarity, and your friend goes and buys an I1 clarity with a K-L color, AND HIS DIAMOND IS MORE BRILLIANT THAN YOURS???!!! That can be YOUR REALITY if you don't buy smart. Currently there are three different types of proportion analyzers on the market today that are available to jewelers and gemologists.
1. The Gemscope Eyepiece Diamond Proportion Analyzer
This is an eyepiece that plugs right into a gemological microscope and allows the grader to determine all the proportions of any given stone. Table, pavilion, crown, girdle, everything except pavilion angles. If the pavilion fall between that 42-45% mark though it's a pretty safe bet the pavilion angles are going to be right too.
There is then the second type of proportion analyzer in which a diamond can be viewed on a translucent screen as you observe the silhouette of the diamond and that is...
2. The Standard Full screen Gem Proportion Analyzer
On both the eyepiece and the screen you are observing all the various scales. The diamond will be rotated around and measured at 8 different points and an average is taken on all measurements. Pretty cool huh? What's sad is that there are a lot of jewelers who don't bother to learn how to grade the cut or purchase the equipment to do the job properly. Using the eyepiece or screen can be a little tedious and take some time, but REMEMBER, THIS IS THOUSANDS OF DOLLARS OF YOUR MONEY! LET HIM TAKE ALL THE TIME HE NEEDS, YOU WANT GOOD PROPORTIONS!
The 2 devices above are now what would be considered the "old fashioned" way of measuring proportions that some appraisers still use with a notable degree of accuracy. However newer devices have been introduced on the market for more accurate measuring of the facets and angles.
The Sarin Digital Proportion Analyzer
This first device is the simplest and most basic of the digital proportions analyzers. It is the least expensive
The Sarin Company (www.sarin.com) specializes in hardware/software solutions that physically measure a diamonds facets and proportions.
This method of grading and determining the proportions is the fastest, the most exact, and the most proficient. A diamond is placed on a small rotating stand inside this piece of hardware which has camera's built into it. The stone is rotated and measured from every angle by the internal camera. This hardware works in conjunction with software which then gives all the results onscreen and can then be printed out for the consumer to observe. Here's the info it gives onscreen.
Notice the part labeled "Report" on the right side.
Calculated Weight: An "estimated weight" of what the diamond should weigh based on the measurements. It's usually within a 1/2pt of the actual weight, if not right on.
The diameter of the diamond. Minimum, maximum and average.
The total depth of the diamond in both millimeters and percentage.
Pavilion Depth: Which, as you have learned is extremely critical to the brilliance.
Pavilion Angles: Proper pavilion depth must always be accompanied by the proper pavilion angles (approx. 40-42 degrees.)
Crown Angles: Also very critical to the diamonds brilliancy and dispersion.
Girdle: minimum, maximum
And last but not least a total cut grade based on the computer's analysis.
What's also nice about a machine like this is it'll show you how all those numbers relate directly to the diamond in question by simply clicking on the "average graph" picture above or a report can simply be printed out. Here's what it looks like on screen.
Printed reports like this.
I don't know about you but if I were ready to drop a few g's on a diamond... I'D DEMAND THIS INFORMATION! It shocks me how many people blindly spend big money on diamonds without this information.