The Gemological Properties of the De Beers Gem-Quality Synthetic Diamonds

Shigley, James E.; Fritsch, Emmanuel; Stockton, Carol M.; Koivula, John I.; Fryer, C. W.; Kane, Robert E.; Hargett, David; Welch, Clayton W.

doi:10.5741/gems.23.4.187

Cited by 43 publications

(52 citation statements)

References 16 publications

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“…These luminescence patterns are related to the relative sizes, differences in impurity content, and different geometric arrangements of the internal growth sectors. We were surprised, however, to see stronger luminescence from the octahedral growth sectors of these crystals than from their cube sectors (in contrast to previous observations; see Shigley et al, 1987). Regardless, this zoning geometry clearly indicates the presence of different types of growth sectors, which identifies the crystals as synthetic.…”

Section: Resultscontrasting

confidence: 52%

“…These two crystals are similar in morphology to the yellow synthetic diamonds described previously (Shigley et al, 1986(Shigley et al, , 1987.…”

Section: Resultssupporting

confidence: 51%

“…Under these conditions, we clearly saw a zoned pattern of luminescence corresponding to the arrangement of different internal growth sectors (as has been reported in yellow synthetic diamonds; see Shigley et al, 1987).…”

Section: Resultsmentioning

confidence: 57%

“…than to longwave U.V. (Crowningshield, 1971;Koiv~ila and Fryer, 1984;Shigley et al, 1986Shigley et al, , 1987Scarratt, 1987;Rooney et al, 1993).…”

Section: Resultsmentioning

confidence: 99%

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Two Near-Colorless General Electric Type-IIa Synthetic Diamond Crystals

Shigley¹,

Fritsch²,

Reinitz³

1993

Gems & Gemology

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Of all the gem-quality synthetic diamonds that could potentially enter the jewelry trade, faceted near-colorless synthetic diamonds are the greatest concern. Not only do near-colorless diamonds represent the vast majority of stones in the jewelry industry, but the techniques the jeweler typically uses to quality grade these stones are different from those needed to separate natural from synthetic diamonds. Yet relatively few near-colorless gemquality synthetic diamonds have been made available for gemological examination, so practical means for identifying them have not been well documented.

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Section: Resultscontrasting

confidence: 52%

“…These two crystals are similar in morphology to the yellow synthetic diamonds described previously (Shigley et al, 1986(Shigley et al, , 1987.…”

Section: Resultssupporting

confidence: 51%

Section: Resultsmentioning

confidence: 57%

“…than to longwave U.V. (Crowningshield, 1971;Koiv~ila and Fryer, 1984;Shigley et al, 1986Shigley et al, , 1987Scarratt, 1987;Rooney et al, 1993).…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Two Near-Colorless General Electric Type-IIa Synthetic Diamond Crystals

Shigley¹,

Fritsch²,

Reinitz³

1993

Gems & Gemology

Self Cite

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“…It is known (Shigley et al 1987) that natural diamonds grow by layers in parallel with the octahedral faces, whereas synthetic diamonds of the metal-carbon syntheses generally grow by layers parallel with both octahedral {111} and cubic {100} faces, forming corresponding growth pyramids. This accounts for the optical and physical inhomogeneity of the MC diamonds in connection with the capture of metallic inclusions into the space between the growth pyramids and an irregular distribution of isomorphic impurities (e.g., nitrogen, nickel) and vacancies within the different growth sectors.…”

Section: Discussionmentioning

confidence: 99%

Peculiarities of diamonds formed in alkaline carbonate‐carbon melts at pressures of 8–10 GPA: Scanning electron microscopy and cathodoluminescence data

et al. 1998

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Summary: Diamond crystallization with both spontaneous and seeded nucleation was realized in the system Na 2 Mg(CO 3 ) 2 -K 2 Mg(CO 3 ) 2 -C (graphite) at 8-10 GPa and 1700-1800 o C. The crystallization products were transparent colorless diamond single crystals of octahedral habit up to 100-150 µm in size. Scanning electron microscopy (SEM) showed that the growing diamond material was precipitated on both octahedral {111} and cubic {100} faces of synthetic and natural diamond seed crystals by layers of octahedral orientation, much like the growth of the natural diamond. The physicochemical conditions for diamond crystallization are interpreted as a crystal growth from carbon solutions in alkaline-carbonate melts. Color cathodoluminescence scanning electron microscopy (CCL-SEM) and cathodoluminescence (CL) spectroscopy studies suggested specific peculiarities of the synthetic "carbonate-carbon"(CC) diamonds resembling natural crystals in comparison with diamonds produced by metal-carbon (MC) synthesis. The main feature of the CC product is the lack, for both spontaneous and seed stimulated diamonds, of surface color cathodoluminescence as in the case for natural diamonds with lower concentrations of nitrogen impurity (type II). The CL spectra of the CC diamonds showed the simultaneous luminescent three-band system -H3, 575 nm, and a weak blue A-band -the H3 band structure of which resembles that of natural diamonds of type IIa.

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Fluorescence of Natural and Synthetic Gem Diamond: Mechanism and Applications

Breeding¹,

Eaton-Magaña²

2019

Encyclopedia of Analytical Chemistry

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Fluorescence is a property exhibited by all states of matter but rarely is it more impressive than the blue gleam emitted when a gem‐quality diamond is exposed to ultraviolet (UV) light. Diamond fluorescence and phosphorescence are a product of atomic impurities like nitrogen and boron that can occur in concentrations as low as several parts per billion, yet still impact the body color and luminescence characteristics. Distribution of fluorescence in gem diamond is different between natural and laboratory‐grown crystals and is often changed by treatments aimed at modifying diamond color, making it a valuable gemological identification tool. While diamond is most readily recognized as a gemstone, its value is even greater in the technology sector where single photon emitting defects in diamond are a key component in today's research on quantum computing and semiconductor applications.

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The Gemological Properties of the De Beers Gem-Quality Synthetic Diamonds

Cited by 43 publications

References 16 publications

Two Near-Colorless General Electric Type-IIa Synthetic Diamond Crystals

Two Near-Colorless General Electric Type-IIa Synthetic Diamond Crystals

Peculiarities of diamonds formed in alkaline carbonate‐carbon melts at pressures of 8–10 GPA: Scanning electron microscopy and cathodoluminescence data

Fluorescence of Natural and Synthetic Gem Diamond: Mechanism and Applications

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