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Not Your Typical Diamond Buying Guide -A new look at the 4C's of Diamond Buying

Not Your Typical Diamond Buying Guide

This buying guide goes into a little more detail than most diamond buying guides you find on the internet. At Sky Diamond Jewelers we believe an educated consumer is the best consumer. So, dive right in...


OK, first things first... Do not rely on a diamond certificate alone, to tell you the quality of your diamond. You are not buying a piece of paper, you are buying a diamond! This would be like buying a car based on the description and never taking it out for a test ride. How would you know if the diamond you receive is as good as the diamond described on the certificate? That’s why we are going to not only give you the basic's of diamonds but go into the nitty gritty details about the 4 C’s that most jeweler's won't tell you about!

Diamond Buying, Loose Stones


// The Basics

Diamonds are graded based on the presence or absence of color. Diamonds with less color have a better grade and will display more colorful fire. A diamond with a color grade of D, E, or F is regarded as colorless. Color grades of G, H, I, and J are considered near-colorless, and can offer excellent values.

// The Not So Basics

So how do I know what color it is that I’m looking at? The truth is it takes a trained eye and years of practice to grade color but you can absolutely gain the basic knowledge, you should compare more than one stone when shopping for a diamond and comparing to a GIA graded stone is a great starting point. Color is most often graded from the side of a diamond because there is less reflective light coming from the diamond and you could get truer feel for its hue. With this said, ask your jeweler to show you a few different diamonds that fall in different ranges of the color spectrum so you have a better idea for color. If he says a diamond is a D color and you see a lot of yellow in the diamond you know to ask a bit more questions. Even when a diamond is certified there have been known to be variations in diamond colors from certificate to certificate. For example, two stones may be graded 'G' color but will have a visible color difference, likely placing them in two separate color grades.

GIA Color Grading Scale


//The Basics

Diamonds are renowned for their ability to transmit light and sparkle so intensely. We often think of a diamond's cut as shape (round, heart/oval/marquise, pear), but a diamond's cut grade is really about how well a diamond's facets interact with light. Cut grade is established by defining the relationship between a diamond's light performance, dimensions, and finish. Even with exceptional color and clarity, if a diamond is poorly cut, it will look dull.

//The Not So Basics

You will see one of these cut grades on a certified diamond:

Poor, Fair, Good, Very Good, or Excellent. Cut is harder to determine. There are two quick tips to consider when determining if your diamond is cut well:

1. Look at how the diamond comes to a point and make sure it’s in the center of the diamond. A poorly cut diamond's culet ( the point at the bottom of the diamond) may be off center.

2. Check the measurements. (Refer to the chart below for average mm sizes per carat weights) If you’re looking at a 1ctw diamond and you know that a well cut 1ct diamond is around 6.4mm – 6.5mm and the stone measures 6.1mm wide then you know that the diamond is deep; and vice versa for a shallow cut diamond.


//The Basics

Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called 'inclusions' and external characteristics called 'blemishes.' Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value.

//The Not So Basics

OK, so let’s get into grading clarity. Same as grading color it takes years and lots of practice to grade diamond clarity yourself but there are always ways to check yourself and references to help guide you. If a diamond is certified, you could simply look at the inclusions that are mapped on the certificate and make sure they match the diamond itself. If a diamond is not certified there are still ways to gauge the clarity of the diamond. The rule of thumb is if you can see a blemish, imperfection or a characteristic of the diamond with your naked eye, the diamond is likely in the 'I' clarity range. Once you get to the VS clarity range, imperfections become very hard to find and to the naked eye you would not notice any imperfections. You should start by using the 10x loupe and looking directly down on the diamond, unlike color you start by looking the diamond face on. Start in the center and scan the diamond for imperfections.

Carat Weight

// The Basics

Carat is a measure of weight, not size, and two diamonds with the same carat weight but different cut characteristics will not appear to be the same size when viewed from the top. Also, in general, it takes about a 20% increase in carat weight before most people will notice a difference in size.

//The Not So Basics

There are 100 points in a carat the same way there are 100 cents in a dollar. So when you hear things like 72 points you know the jeweler means .72 carats or just under 3/4 of a carat. Diamonds are priced based on rarity, a 1/2 carat diamond will not be 1/2 the cost of a 1 carat diamond because a 1 carat stone is much more rare. There is a premium for a 1.00 carat diamond because it's a desired size and brings you into a new cost bracket. To get a great value, consider buying a diamond that is just under one carat. For example, find a .89-.97 carat diamond where the mm size is almost identical to a 1.00 carat diamond, but you stay under the price increase. This concept is the same for 1.50 and 2.00 carat diamonds.


Believe it or not, this just scratches the surface of what there is to know about shopping for diamonds and getting to know what it is that you're looking at. You should always consult with a trusted jeweler. If you have any questions regarding diamonds at all, give us a call and we will guide you in the direction that's best for you!

* Sources include: Personal Knowledge of Isreal Morales,, and GIA

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