What are the yellow tones that I see in the diamond video?
Hi Danny, I was just about to pull the trigger and purchase the 1.124 carat, G-color, SI-1 clarity, Brian Gavin Signature round diamond, but then I noticed some yellow tones in the video provided on the diamond details page; are these indications that the diamond is going to look yellow? My girlfriend really wants a diamond which is at least a carat, and we want it to face-up white and eye clean. I thought that a G-color diamond wouldn’t show yellow, do I need to increase my budget and buy something which is colorless? To ensure you’re seeing what I’m seeing, I’m referring to the patches of yellow which are visible in the two and nine o’clock positions. Advice appreciated. - D. Chang
What creates dispersion within diamonds?
One of the least understood diamond concepts is that of dispersion, which is also commonly known as “fire” because the original light sources which diamonds were cut to perform under were fire light and candle light. The simple explanation of dispersion is that it is when white light enters a diamond, and separates into spectral hues which are directed up towards our eyes, and seen in practically every color of the rainbow. The proportions of a diamond, which is kind of like the outline of the diamond as seen from a side profile, as pictured here, control the volume of light return and contribute to the overall sparkle factor of a diamond.
The proportions grade of the 1.124 carat, G-color, SI-1 clarity, Brian Gavin Signature round diamond which you are considering is AGS Ideal, and is a contributing factor to the overall cut grade of AGS Ideal-0, which also takes into account the polish grade, symmetry grade, and the light performance exhibited by the diamond.
The effect of optical symmetry upon diamond dispersion:
The symmetry grade which appears on diamond grading reports issued by gemological laboratories such as the AGSL and GIA, are for “meet point symmetry” which takes into account the consistency of facet shape and how precisely the facet junctions are aligned and “meet” at the points. Optical symmetry refers to the degree of precision which the facets are indexed, or spaced apart from each other as they are positioned around the diamond, in addition to the overall size of the facets, and their alignment to one another 360 degrees around the diamond and from top to bottom. The degree of optical symmetry within a diamond is a critical factor of both light return and the sparkle factor.
A diamond brilliance study conducted by the American Gem Society Laboratory (AGSL) which was published in the September 2007 issue of Optical Engineering magazine, indicates that more precise levels of optical symmetry; such as the level of precision which is necessary to produce the crisp and complete pattern of hearts and arrows, pictured above, which is visible within the 1.124 carat, G-color, SI-1 clarity, Brian Gavin Signature round diamond when viewed while unmounted through a hearts and arrows scope; produces a higher number of virtual facets, which in turn produces more sparkle, and makes the diamond appear brighter with more intense flashes of light!
Obviously as the white light which enters the diamond, is dispersed into all the spectral hues of the rainbow, there will be flashes of blue, red, green, pink, and even yellow, visible throughout the diamond as you have seen in the video of the diamond which is provided on the diamond details page.
It is also important to note, that since a diamond is essentially a prism, it will pick up and reflect whatever colors are present within the room where it is being viewed, thus our perception of diamond color is always subject to the conditions which it is being evaluated under.
