Does the thought of purchasing a diamond ring overwhelm you? Don't think you know enough about certificates, authenticity, inclusions, and grading scales? Or do you know the basics, but need a refresher course?  A good understanding of diamonds is necessary before you begin shopping. Our guide gives you the basics -- the all-important "4C's" of diamond quality (cut, clarity, color, and carat weight), special information on "fancy shapes,"  life size carat weight images for buying online & much more.

Popular Diamond Shapes

Round Diamonds This shape has set the standard for all other diamond shapes, and accounts for more than 75% of diamonds sold today. Its 58-facet cut, divided among its crown (top), girdle (widest part) and pavilion (base), is calibrated through a precise formula to achieve the maximum in fire and brilliance. 

Princess Diamonds The Princess cut is the second most popular cut shape for diamonds, next to a round brilliant.[citation needed] The face-up shape of the princess cut is square or rectangular and the profile or side-on shape is similar to that of an inverted pyramid with four beveled sides. The princess cut is a relatively new diamond cut, having been created in the 1960s. It has gained in popularity in recent years as a more distinctive alternative to the more popular round brilliant cut, in which the top of diamond, called the crown, is cut with a round face-up shape and the bottom, called the pavilion, is shaped similar to a cone. A princess cut with the same width as the diameter of a round brilliant will weigh more as it has four corners which would otherwise have been cut off and rounded to form a round brilliant. 

Marquise Diamonds An elongated shape with pointed ends inspired by the fetching smile of the Marquise de Pompadour and commissioned by the Sun King, France's Louis XIV, who wanted a diamond to match it. It is gorgeous when used as a solitaire or when enhanced by smaller diamonds 

Emerald Diamonds This is a rectangular shape with cut corners. It is known as a step cut because its concentric broad, flat planes resemble stair steps. Since inclusions and inferior color are more pronounced in this particular cut, take pains to select a stone of superior clarity and color. Learn more about the Emerald Cut Diamond 

Radiant Diamonds Trimmed corners are the signature of this diamond, and they help make the radiant-cut a popular and versatile choice for jewelry. A radiant-cut looks equally beautiful set with either baguette or round side-diamonds. Radiant-cut diamonds can vary in their degree of rectangularity. To find the dimension of radiant you want, look for the length-to-width ratio in our interactive diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top. 

Oval Diamonds An oval diamond has beautiful brilliance that's similar to a round diamond. Oval diamonds are also very popular as their length can accentuate long, slender fingers. To find the dimension of oval you want, look for the length-to-width ratio in our interactive diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top. 

Heart Diamonds The heart is the ultimate symbol of love. The unique look of the heart-shaped diamond helps make it a distinctive choice for a variety of diamond jewelry. When choosing a color grade, consider that while the price of a J-color heart shaped diamond is exceptional, color may be slightly visible in its corners. To find the dimension of heart-shape you want, look for the length-to-width ratio in our interactive diamond search and on each diamond's detail page. The length-to-width ratio will determine the diamond's outline, or what it will look like when viewed from the top. 

Pear Diamonds A hybrid cut, combining the best of the oval and the marquise, it is shaped most like a sparkling teardrop. It also belongs to that category of diamond whose design most complements a hand with small or average-length fingers. It is particularly beautiful for pendants or earrings. Learn more about Pear Shaped Diamonds 

Asscher Diamonds This beautifully unique shape is nearly identical to the emerald-cut, except that it is square. Also, this shape has a pavilion that is cut with rectangular facets in the same style as the emerald-cut. If you choose SI-clarity be sure to view the clarity plot on the diamond certificate, because this shape highlights the clarity of the diamond. When choosing a color grade, consider that while the price of a J-color non-round diamond is exceptional, color may be slightly visible in its corners. 

Trillion Diamonds This is a spectacular wedge of brittle fire. First developed in Amsterdam, the exact design can vary depending on a particular diamond's natural characteristics and the cutter's personal preferences. It may be a traditional triangular shape with pointed corners or a more rounded triangular shape with 25 facets on the crown, 19 facets on the pavilion, and a polished girdle. It is definitely for the adventurous. 

Cushion Diamonds An antique style of cut that looks like a cross between an Old Mine Cut (a deep cut with large facets that was common in the late 19th and the early 20th centuries) and a modern oval cut. Learn more about the Cushion Cut Diamond