How to Choose Your Diamond

How to Choose Your Diamond

In an ideal world with unlimited budgets and an infinite supply of diamonds, everyone would have beautifully cut “D Flawless” diamonds. In the real world every diamond is unique. There are plenty of gorgeous diamonds to go around – you just need to know how to find one. 

Choosing a diamond is about balancing several factors to make the most of your budget. Each factor contributes to the beauty and prestige of your diamond. Please feel free to contact us if you have any questions about diamonds or choosing your diamond. 

Factor 1: Carat Weight

People often use the word Carat when discussing how big a diamond is, however “Carat” actually refers to the weight of a diamond.

There is no rule as to what carat weight you should buy, but you’ll doubtless have heard that "bigger is better." If you ask us, we think bigger is great but you shouldn’t forget about the other aspects of a diamond's quality.

A useful tip: if you're looking at Certified Diamonds using our Diamond Finder, you may find it valuable to compare the diameters of different diamonds. Since every diamond is individually cut, some may appear larger than others of the same weight.

Factor 2: Shape

Approximately 75% of diamonds sold worldwide are Round Brilliants. Rounds diamonds are the most popular, most brilliant, and most expensive. If you are purchasing a diamond as a surprise, Round Brilliant is generally your safest bet!

There is no real hierarchy of shapes being better or worse – it is truly a matter of personal preference. Princess Cuts are the second most popular, and a classic alternative to round diamonds. Cushion Cuts are trendy and have a beautiful vintage look. If you want something different but not too crazy, try an Oval Cut, Asscher Cut, or Radiant Cut diamond. 

While no shape is better, there are some significant differences between shapes. Take for example, the radiant cut vs the emerald cut. Though they are a similar shape, the extra facets of the radiant cut give it additional fire and sparkle. If you prefer the emerald cut's understated elegance, consider that it's easier to spot any imperfections and select a higher clarity grade.

These two diamonds below were both graded by the same lab. I picked them out because they have very similar black carbon spots. Note how much easier they are to see in the Emerald Cut diamond:

Another tip: Diamonds (even round diamonds) may not be perfectly symmetrical. It's nothing to worry about if your diamond's width does not precisely match its height, but if your diamond is much longer than it is wide it may not be what you're expecting. This is especially the case in shapes like Cushion and Oval, where a more asymmetrical diamond might look “skinny”, with much of the fire and brilliance concentrated at the ends.

Factor 3: Cut

"Cut” refers to a diamond's finish and proportions, and is critical in determining its beauty. Getting
the angles right ensures a beautiful diamond that’s full of life. In many cases it can be more difficult to spot inclusions in a fiery, brilliant diamond – just as I've illustrated with the Radiant and the Emerald cut above.

Cut is generally graded in five categories: Poor, Fair, Good, Very Good, and Excellent. Excellent is the highest graded awarded by GIA (whereas other labs may use terms like "ideal" or numbers like "0"). If you want to play safe, stick to “Very Good” and “Excellent” cuts when you choose your diamond. If you're considering a diamond with a "Fair" cut grade, I recommend e­mailing or calling us first so we can view the diamond before you buy.

Here I should also mention that there is a style of round brilliant cut called "Hearts and Arrows," which has given us our company name. A Hearts & Arrows cut refers to a round brilliant diamond cut to an extremely precise degree of symmetry. When viewed through a special scope, H&A diamonds exhibit a pattern resembling arrows when viewed from the top, and hearts when viewed from the bottom. Diamonds that achieve a Hearts & Arrows cut are known for displaying exceptional fire, brilliance and scintillation. 


Factor 4: Clarity

Almost all diamonds have naturally­ occurring features called “inclusions.” Inclusions form as the diamond crystallizes deep underground, and they are unique to each diamond. They take many different forms, and can help you identify a diamond as your own. However, large and prominent inclusions can detract from the beauty of a diamond.

Here is the GIA Diamond Clarity Grading Scale:


As described by GIA's website, the GIA Diamond Grading Scale has a total of 11 specific grades:

  • Flawless (FL): No inclusions and no blemishes visible under 10x magnification.
  • Internally Flawless (IF): No inclusions visible under 10x magnification.
  • Very, Very Slightly Included (VVS1 and VVS2): Inclusions so slight they are difficult for a skilled grader to see under 10x magnification.
  • Very Slightly Included (VS1 and VS2): Inclusions are observed with effort under 10x magnification, but can be characterized as minor.
  • Slightly Included (SI1 and SI2): Inclusions are noticeable under 10x magnification.
  • Included (I1, I2, and I3): Inclusions are obvious under 10x magnification which may affect transparency and brilliance.

If your budget is limited, I recommend buying "SI1" clarity or better. With close inspection you can usually spot the inclusions in an SI1-graded diamond, but these inclusions will most likely not be easy to see. If you want to be sure your diamond will look “eye clean”, even up close, I recommend selecting a VS2 clarity diamond or better. Imperfections in VS+ clarity stones are so minute that they are rarely ever seen by the naked eye.

It's also important to know that there are different types of inclusions, and not all are created equal. If your diamond certificate has an "inclusion map," check where the inclusions are. Try to find a diamond with inclusions near the edge where they will be masked by sparkle or hidden by the setting of your diamond.

To compare three diamonds from our current inventory (at time of writing): 

Factor 5: Colour

The term "colour" usually refers to how much warm tint is in a diamond. The scale ranges from D (colourless) to Z (very strongly tinted yellow or brown). Pure white diamonds are considered more desirable, and are more expensive. Warmer-­hued diamonds (such as K, L, and M) are not necessarily less attractive, but they are significantly less valuable.

Conventional wisdom is to select J colour or better. Personally, I love G colour diamonds ­- they hit the "sweet spot" where most people will not notice colour in the diamond unless they're doing a direct comparison. However, an H-J colour diamond that is well cut and has a lot of life can give you a beautiful diamond at a bargain price.

Depending on how they are cut, different diamonds will display colour differently. This is why colour grades are assigned by looking at a diamond upside-down. Generally, the more ­brilliant your diamond is, the less noticeable a hint of colour will be.

I have drawn a little chart based on my experience with GIA colour grades. Please note monitor colours will vary, and this chart may not be accurate on your screen.


Factor 6: Fluorescence

Fluorescence has a bad rep, and most of it is unfair. Diamond Fluorescence refers to how a diamond responds when subjected to ultra­violet light. Fluorescent diamonds can glow any one of several colours, but the most common is blue.

In rare cases fluorescence can cause your diamond to have a milky appearance when viewed in direct daylight. This is most often the case with strong or very strong fluorescence and D/E/F colour diamonds.

However, there are many cases where blue fluorescence is a positive thing. Imagine you were shining a blue light on a yellow diamond... the blue tint can make your diamond look whiter. See these two similar diamonds from our inventory: 

The diamond in the right-­hand side shows less yellow, and thus appears to be a higher colour grade. If your diamond falls in the "near colourless," "lightly tinted," or "tinted" range I recommend looking for medium blue or faint blue fluorescence.

Warning: Green, red, and yellow fluorescence are rare, and they will not have the same benefit. If you are interested in a diamond that has any green, red, or yellow fluorescence, or strong or very strong blue fluorescence, contact us prior to making your purchase so we can check the diamond first in natural daylight. 

Factor 7: Grader 

This should always be your first question: Says who? Every diamond grading laboratory has different standards, so comparing diamonds graded by different sources is extremely unreliable. One grader might grade a diamond K SI2, and another might call that same diamond F VS2. I know that sounds crazy, but I see it happen all the time.

The most reputable and consistent grading laboratories are GIA, AGS, IGI, and HRD. GIA is considered the global standard worldwide. AGS is a popular alternative in the U.S.A. while IGI and HRD are more common in Europe.

EGL is tricky because there are EGL labs all over the world, and some of them do a great job while others can be less reliable. I strongly recommend caution when buying an EGL certified diamond unless it's from EGL-­USA. 

In New Zealand a lot of diamonds are assigned grades by valuation companies and in-­house graders. If your diamond does not come with a report from a major laboratory, you should always ask where the grader trained. He or she should be certified by a major grading laboratory: GIA, AGS, IGI, or HRD. Be smart and be cautious about reports done by uncertified shop owners, salespeople, or valuation companies.

Ultimately, you don't want a beautiful grading report - you want a beautiful diamond. Overly-flattering (or downright dishonest) reports are meant to benefit diamond sellers, not diamond buyers. When shopping online, savvy shoppers only compare diamonds against other diamonds from the same grading laboratory.

At Hearts & Arrows, most of our diamonds over 0.15 carats come with a report from GIA, AGS, IGI, or HRD. Our in-house grading is done by a GIA certified master diamond grader. We chose him because he's the best of the best, so you can rest assured that all of the diamond lingo you'll read in our product descriptions is up to his tough standards. 

Selecting your Diamond

We have a Diamond Search tool which allows you to browse through thousands of available diamonds. You can select a diamond, then (if you wish) pick out one of our hundreds of ring settings to go with it. We will set the diamond and deliver it to your door.

Usually when you purchase a diamond from an online retailer, that diamond is sitting in somewhere across the globe and the retailer has no idea what it actually looks like. With a purchase as important as your diamond, we don't want to rely on chance to get it right. When you purchase a diamond, we will personally inspect it before we send it to you, checking all of the factors I've explained above. If we don't think you'll be impressed, we'll let you know and suggest some better options.

We also sell complete Diamond Engagement Rings. They are designed to take all the guess­work out of your purchase. We personally hand­ select these diamonds from our top suppliers, picking only the best. You won't believe how good these diamonds look ­and their prices are unbeatable.

Click here to try our Loose Diamond Search. Or visit our Engagement Rings page to view our hand­picked diamonds already in settings. 

July 23, 2013 by Danielle Saudino
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