Marquise Diamond Buying Guide


When it comes to choosing a length to width ratio for your Marquise Diamond, remember this decision is primarily based on personal preference. Above all, you want the diamond to look stunning to the naked eye and match the style of the wearer.

Popular length to width ratios for Marquise Diamonds range from 1.70-2.15. Length to width ratio can be determined by dividing the length of a diamond by its width. For instance, if a diamond maintains a length of 5mm and width of 3mm, the length to width ratio is 1.67.


Selecting any diamond should include thorough consideration of each of the 4 C’s (Cut, Clarity, Color and Carat).

  • I2 – Inclusions
  • I1 – Inclusions
  • SI2 – Small Inclusions
  • SI1 – Small Inclusions
  • VS2 – Very Small Inclusions
  • VS1 – Very Small Inclusions
  • VVS2 – Very Very Small Inclusions
  • VVS1 – Very Very Small Inclusions
  • IF – Internally Flawless


Imagining how big certain carat weight is can be difficult. We decided to make it easy for everybody and made this side by side comparison to a US quarter.

Common Marquise Diamond Cut Problems

While many cut elements can make a Marquise Diamond undesirable, we’ve highlighted common problems in the images below and compare them to an ideal cut Marquise.


This diamond contains a distinguishable bowtie: the dark area running across the diamond’s center. We expand on the bowtie effect later in this article, but all in all, it takes away from the diamond’s beauty and becomes the unwanted point of attention. This diamond is also cut slightly too wide, making it more broad than elegant.


The diamond is cut like a narrow football and lacks strong eye appeal. Its table is too small and its crown is too high (the portion above the diamond’s girdle). These elements limit both white and colored light reflection, making the diamond less than radiant.


While length to width ratio depends on personal preference, this diamond has an appealing shape at a 1.90 ratio. It is cut with a sizeable table, allowing for ample light reflection. There is no distinguishable bowtie (dark space running across the diamond) and it’s noticeably more beautiful than the other two diamonds.


When it comes to the Marquise Diamond, Color is similar to Clarity: more weight should be placed on the actual appearance of the diamond, rather than a specific grading given by a lab entity.

The GIA grades diamonds for Color from D to Z. A grading of D represents the most colorless while Z diamonds contain easily noticed yellow or brown tint. The visible difference between two adjacent grades, such as G and H, is often non-existent to the naked eye, which is why we recommend reviewing the diamond yourself or having an expert assist you.

Bowtie Effect in Marquise Diamonds

Due to their elegant and elongated shape, nearly all Marquise Diamonds contain a bowtie effect. The dark space, referred to as the bowtie, stretches across the diamond’s center and can impact the beauty of the stone. Bowtie severity differs across Marquise Diamonds. In some cases, the bowtie is noticeable to the naked eye, while other times it’s nearly invisible.

Look for a Marquise Diamond without a dominant bowtie, as this will detract from the magnificence of your stone. We highly recommend a diamond expert review any Marquise before purchase.

In the images below, notice the significant difference between a bowtie and non-bowtie diamond.