30% Off Select Lab Grown Diamonds >

Signature Diamonds

While we no longer offer Blue Nile Signature diamonds, we introduced Astor by Blue Nile™ diamonds, which are cut specifically to maximize brilliance. These diamonds are tested by two respected independent gemological labs: GIA for quality and GemEx for light performance. Because our standards are so high, only 1 in 1,000 diamonds qualify for the Astor by Blue Nile™ name, making them exceedingly rare.
To ensure the highest quality, we start with the finest uncut diamond rough found in nature. Because of its natural shape 
and crystalline structure, the diamond rough is first cut in two. Then each piece is meticulously analyzed by our master 
diamond gemologists, who mark it for facets with proportions that will produce the most brilliance.
Diamond cuts are planned for an uncut diamond rough using a diamond cut plot.

Brilliance Is Key 

The dimensions of the Blue Nile Signature diamond are very specific, leaving no room for error. If a diamond is cut even slightly out of proportion, it may yield more carat weight but it will not be as brilliant. In fact, to create a diamond with this much brilliance, as much as 74% of the diamond rough must be cut away. The Blue Nile Signature round diamond comes with an additional certification from the Gem Certification & Assurance Lab that shows the exceptional amount of brilliance emitted from these diamonds.

image.     image.   image

Perfect Proportions

Proportions affect how light travels within the diamond. Diamonds that are cut too shallow and wide, or too deep and narrow lose light out the sides or bottom, causing the diamond to lose brilliance. Blue Nile Signature Diamonds are cut to perfect proportions, allowing the diamond to reflect the maximum amount of light a diamond can produce.

Exceptional Symmetry

The alignment of a diamond's facets, or symmetry, also has a strong effect on diamond brilliance. Each facet is 
like a mirror. When the facets are symmetrically aligned, all of that reflected light is focused directly at your eye. In the 
illustration to the left, the diamond on the left has poor symmetry and the facets do not align. As a result, light is 
misdirected within the diamond and brilliance is lost. The diamond on the right is a Blue Nile Signature Diamond, its 
facets are symmetrically aligned and cut to standards that ensure its brilliance is emitted evenly.                                                                                                    
Illustrative representation of facet symmetry in a diamond.

Graded And Certified

All Blue Nile Signature collection loose diamonds are certified by GCAL in addition to being graded by the GIA or AGSL. This provides you a second authoritative analysis of your diamond. GCAL also verifies that your diamond meets all the specific quality requirements of the Blue Nile Signature Collection.
An example of a GCAL certification


All Signature stones have been screened for Gemprint and must be registered at Gemprint®. Many insurance companies offer a 10% discount if your diamond is registered in the Gemprint® International Registry at Gemprint.com. For a list of companies, see Insurance Discounts