Understanding Diamonds and Light

The GIA has studied and documented the relationship between light and a polished diamond for many years.  Research has allowed them to understand how different facet sizes, arrangements, and angles could either improve or reduce a diamond’s appearance.   This understanding led to the development of the GIA Diamond Cut grading system.

When diamonds and light interact the results are amazing.  The relationship between diamonds and light lies in how much light hits the surface of the diamond, enters the diamond, and how the light reflects back from the diamond.  The proportions of a polished diamond (its angles and measurements) and the relationship between them have an extraordinary effect on how light performs when it strikes the diamond.

A diamond has three visual characteristics: brightness, fire, and scintillation. Brightness (aka brilliance) is the amount of white light returned from the diamond to the observer, fire is the display of spectral colors created when the white light strikes the diamond’s facets, and scintillation is the flashes of light and contrasting dark areas seen when a diamond, the light source, or the observer moves.

A well-cut diamond will get the most out of its interaction with light.  Well-cut diamonds are brighter and more attractive than poorly cut diamonds even if weight, color, and clarity are the same.

To learn more about diamond proportions visit our diamond education section.

diamonds and light

Gold Karat Weight and Gold Fineness

The purity of gold is described as karat (US) or fineness (Europe).  Pure gold is alloyed (combined) with other metals to make it more affordable, durable, and to change its color.   The minimum karat weight that can be sold differs from country to country.  In France and Italy gold must be at least 18kt to be called gold.  In the US and Japan gold must be over 10kt to be considered legal.  The two most common karat marks are 14kt and 18kt.  18kt is considered the international and US standard for high quality jewelry.  In India 22kt gold is popular because it is considered a monetary investment and the deep yellow color is more popular over the lighter alloyed shades of gold.

Gold Content and Markings Chart

US Karat Marking

Parts Gold Gold % International Fineness Marking
24k or 24kt 24/24 99.9% 999
22k or 22kt 22/24 91.7% 916 or 917
18k or 18kt 18/24 75.0% 750
14k or 14kt 14/24 58.3% 583 or 585
12k or 12kt 12/24 50.0% 500
10k or 10kt 10/24 41.7% 416 or 417
9k (Not sold) 9/24 37.5% 375

Is 14kt or 18kt Gold Better?

14kt Gold Pros and Cons

Pros – less expensive, wears better

Cons – may discolor or tarnish due to the lower percentage of gold, may cause allergic reaction due to metal alloys

18kt Gold Pros and Cons

Pros – more gold – less alloys which makes it more valuable, less likely to cause allergic reaction

Cons – some alloys used may not be as hard and strong as with 14kt

To learn more about gold and other precious metals visit our jewelry education section.

How to Choose the Perfect Diamond Shape for Your Engagement Ring

Choosing the perfect diamond shape for your engagement ring is important and before making your decision you should consider much more than what shape you like best.  Your engagement ring will be one of the more significant purchases you’ll ever make and considering all your options is essential.

What diamond shapes are there?

diamond shape chart

Before making your decision familiarize yourself with each shape and the differences between them.  Do you like the fire and brilliance of the round brilliant cut, radiant cut or princess cut, the romantic look of the cushion cut, heart, or oval cut, or the classic long lines of the emerald cut.

While personal preference is extremely important here are some other things to consider.

Things to consider

Will the shape be practical to your life style?  Based on your life style certain settings may be better than others.  For example, if you work in the medical profession a diamond shape that can be set in a low profile setting may work better for you.

Size of your fingers and hand –certain shapes will enhance certain features.  For example, the oval elongates your fingers.   Also, a 1.00ct round brilliant will look much different than a 1.00ct emerald.

The quality of the diamond – we always recommend quality over weight.  Certain shapes will need to be purchased in a higher cut, clarity, and color grade than others.  For example, the clarity characteristics in a round brilliant will be less visible than in an asscher or emerald.

After choosing the perfect diamond shape for you make sure you take a look at several setting options.  You’ll want to find a setting that shows off your center stone and doesn’t hide it.

To learn more about diamond shapes, visit our diamond education section

What is a Cushion Cut Diamond?

The Cushion cut diamond is unique with its rounded corners and larger facets and is also known as a pillow cut or candlelight diamond.  The Cushion cut is an antique cut that is a cross between the Old Mine Cut popular in the late 19th Century, early 20th Century and an Oval cut diamond.   This cut provides for a classic look and is not as brilliant as the more modern cut diamonds.  The Cushion has large open facets so clarity and color are important factors when considering this cut.  The recommended length to width ratio for this diamond shape is 1.25 – 1.30.   A ratio between 1.0 – 1.05 offers a square look whereas a ratio greater would offer a more rectangular look.

cushion cut diamond

Since the shape of the cushion is unique they look great set in a solitaire setting, a three stone with something different like oval side stones, or a very simple channel setting.  With this shape stone you don’t want the setting to distract from its beauty.

What is an Emerald Cut Diamond?

The Emerald cut diamond received its name when a diamond cutter chose to cut diamond rough in the shape of an Emerald using the same method as they would for cutting an Emerald shaped gemstone.  Emerald shapes are cut with “stepped” facets, which means the facets resemble steps on a staircase.

emerald cut diamondThe Emerald cut provides for a very elegant classic look and is known for its long lines.  The pavilion (bottom portion of the stone) is cut with large rectangular facets to create an open effect or optical appearance.

Since Emerald cut diamonds are designed with larger facets, you need to be sure that you are familiar with the qualities of a good cut.  Like the Asscher cut you always want to choose cut, color, and clarity over weight.  An Emerald diamond makes a beautiful engagement ring as a solitaire or set with other stones.

To learn more about Emerald cut diamonds visit our diamond education section

What is an Asscher Cut Diamond?

The Asscher cut diamond was developed in 1902 by the Asscher Brothers of Holland and is a variation of an Emerald cut.  The Asscher cut is a stepped square cut also known as a Modified Square Emerald cut.   This cut offers a small table (largest facet on a stone) high crown (top portion of the stone) deep pavilions (lower portion of the stone), and cut corners.   With its 72 wide step facets it resembles that of an octagon and sparkles like the Round Brilliant.

The Asscher was designed to draw your eye to the center of the stone.  Because of this, cut, color, and clarity are very important factors to consider when choosing this cut.  Always purchase the best stone within your budget.  When choosing an Asscher weight should be the last thing you consider.

To learn more about Asscher cut diamonds visit our diamond education section

Asscher Cut Diamond

Three Stone Engagement Ring

Once known as an anniversary ring, three stone engagement rings have gained popularity over the past several years.  A three stone engagement ring represents a couple’s relationship – the past, the present, and the future.

The three stone engagement ring contains just that; 3 stones.  The traditional three stone design is a plain metal band with prong set white diamonds.  The diamonds are all the same shape and color with the center stone being slightly larger and set higher than the two side stones.

Today, three stone settings are available in a variety of designs.  While the traditional three stone is still extremely popular many couples are choosing settings with side stones of a different color or shape.  Prongs can be replaced with bezels and plain bands replaced with scroll work or small accent diamonds.

Creating a Three Stone Anniversary Ring Using Your Own Engagement Diamond

If you’re creating a three stone for an anniversary ring you have some options.

1. Use your engagement diamond as a side stone representing the past and choose a new center stone and second side stone as the present and the future.  The new center diamond should be slightly larger than the side stones.  When choosing new diamonds you’ll need to stay within the same color range if purchasing white diamonds.

2. Use your engagement diamond as the center stone and purchase two new side stones.




Types Of Wedding Bands to Wear With a Three Stone

You have some options here as well.  If you want to wear your three stone on the same hand as your wedding band or your right hand a five or seven stone wedding band or a diamond eternity ring will match perfectly.

diamond eternity ringdiamond eternity ring


Creating your own engagement ring

Create your own designer engagement ring

It’s so easy to create your own designer engagement ring.  Browse through an amazing collection of designer engagement ring settings and a selection of over 30,000 GIA certified diamonds and find the perfect match.

We have every style of settings including solitaires, settings with sidestones, ranging from round and fancy-shapes to delicate micro-pave settings, and much more.

Our wedding ring collection features diamond wedding rings, diamond eternity rings, three stone wedding rings, Tacori wedding rings, and more.  Shop our entire wedding ring collection to find the perfect ring

Create your own engagement ring in three easy steps

See our Creating Your Own Designer Engagement Ring guide

The 4Cs of Diamonds: Diamond Cut

Of the 4Cs, cut is the most important characteristic of a diamond and it has the greatest overall impact on a diamond’s beauty.  Diamonds have the unique ability to manipulate light (aka fire, sparkle, and brilliance) that can only be realized with an extremely high level of accuracy during the cutting and polishing process.  Nature dictates color and clarity, but humans affect the cut.  When cutting diamond rough, the cutter not only considers the proportions of a diamond, but the craftsmanship of overall symmetry and polish as well.  Light enters and exits though the crown reflecting from one facet to another.  A diamond that is cut too shallow or too deep will not reflect light properly and the diamond will not be as brilliant as a diamond with an excellent cut grade.

Diamond’s Light Return

diamond cut chart

In early 2005, GIA (Gemological Institute of America) introduced a diamond cut grading system for round brilliant cut diamonds in the D-Z color range and flawless to I3 clarity range.  In January 2006, these new cut grades ranging from excellent to poor were added to all GIA diamond certificates (aka diamond plot).  To achieve the cut grading system, GIA calculated the cut results for 38.5 million cut proportion sets based on the evaluation of seven components.  The first three were related to appearance and brightness and the last four were related to overall craftsmanship.

GIA Cut Grades


Very Good




When purchasing a diamond, we recommend purchasing the best possible cut grade within your budget.  Unlike color and clarity; which are personal preferences, cut is extremely important.

Visit our education section for more on diamond cut.

The 4Cs of Diamonds: Diamond Weight

Diamond weight is described using two terms: carat and point.   Carat is determined by measuring the distance across the top of diamond and is always listed in millimeters.  When measuring diamond weight it is important to factor in the cut grade.  In a well-cut diamond, the maximum amount of light enters and exits through the table making the diamond look larger than a poorly cut stone.

Like color and clarity, carat weight is a key factor in determining the value of a diamond. Diamond prices vary by carat weight increasing at the full and half-carat weights.  Diamonds just below these weight changes will be less costly and a majority of the time size is undetectable.  For example, a 1.00ct diamond will be in a different price point than a .98ct diamond, but the size will not be noticeable.   Also, since larger diamonds are more rare and costly than smaller diamonds a 1.00ct single diamond will cost much more than several smaller diamonds equaling a total carat weight of 1.00ct.

Diamond Measurements

Carat = 100 points or 200 milligrams

Point = 0.01 or one-hundredth of a carat

diamond weight chart

What carat weight is right for her?

There are several important factors to keep in mind when determining carat weight.

Price – diamond cut, we feel, is the most important of the 4Cs and you should always choose a well cut stone over weight.  If carat weight is important to you and you would like a larger stone, you have some flexibility in terms of price with color and clarity.

Finger size – a 1.00ct diamond will look much larger on someone with a size 4 finger than a size 8 finger.

Setting – certain settings can make a diamond appear larger than it actually is.  Our personal shoppers can help you determine which setting is right for you if you don’t already have something in mind.

Visit our education section for more on diamond weight