Defects_2_Vis Flashcards
Describe defect.
Diamond contain both yellow causing H3 503.2 nm peak and pink-to-red-causing 550 nm band defects.
Describe defect.
Absorption band 480 nm defect, produces saturated orangy yellow to yellowish orange colloration.
Describe defect.
C centers cause absorption within the ultraviolet (UV) region that extends into the blue end of the visible spectrum, producing a more saturated yellow or orange-yellow.
Describe defect.
The 741 nm GR1 defect often causes green color in diamonds. This defect combined with nitrogen related defects absorbs the blue and red parts of visible light to make the stone green.
Describe defect.
A: Trans. window 415-478, GR1 741nm
B: Trans. window 440-550nm, GR1 741nm
C: N3 415nm, N2 478nm, trans window 490-550nm, GR1
In comparison, fewer nitrogen-related defects result in a more pure blue color.
Describe defect.
H3 color center 503.2 nm, absorbs visible light in the blue end of the spectrum and generates a yellow bodycolor.
Describe defect.
The components of H3 (left) and H4 (right) color centers
Describe defect.
Absorption band 650nm+ H-related defect combined with nitrogen-related absorption
produces a green color component.
Describe defect.
Absorption 551 nm and 835 nm hydrogen related defects results from two broad absorption bands producing two transmitted colors in the blue and red regions of the visible spectrum.
Describe.
IIB - boron is the most common cause of blue bodycolor. Diamonds contain enough boron atoms to absorb the red portion and
beyond of the spectrum, transmitting a blue color.
Describe defect.
The N3 defect and color center is composed of three nitrogen atoms surrounding a vacancy. This defect causes the diamond to absorb blue light in the visible range and transmit the rest. This selective absorption colors the diamond yellow.
Describe defect.
A: N3 415nm defect, H3 503 nm and 550nm band defects
B: 550 nm deformation-related absorption.
Diamond at the top absorbs part of the blue portion of the spectrum, bottom diamond transmits this portion. The colors of the diamonds vary.
Describe defect.
N3 415nm and N2 478nm defects.
N3 causes the diamond to absorb blue light in the visible range and transmit the rest. Diamonds that gain their color due to the N3 and its associated absorption features are referred to as “cape” in the trade
Describe defect.
Absorption band 650-750nm Nickel-related defects together with nitrogen-related defects can cause green color in diamond. The absorption from the nitrogen related defects is quite strong, so it often produces a yellow component in the bodycolor.
Describe defect.
575nm & 637nm NV defect On rare occasions, a single nitrogen atom associated with a vacancy colors a natural pink diamond. These diamonds often have pale but uniform pink color and are type IIa. Natural pink diamonds colored by the
NV defect are extremely rare; however, NV defects are almost exclusively the cause of color in treated and lab-grown pink diamonds.
Describe defect.
Vacancy cluster most brown color in diamonds results from vacancy clusters (40-60 vacancies) that absorb light across the spectrum decreasing toward the red end.
