Identification
Early diamond identification tests included a scratch test relying on the superior hardness of diamond. This test is destructive, as a diamond can scratch diamond, and is rarely used nowadays. Instead, diamond identification relies on its superior thermal conductivity. Electronic thermal probes are widely used in the gemological centers to separate diamonds from their imitations. These probes consist of a pair of battery-powered thermistors mounted in a fine copper tip. One thermistor functions as a heating device while the other measures the temperature of the copper tip: if the stone being tested is a diamond, it will conduct the tip’s thermal energy rapidly enough to produce a measurable temperature drop. This test takes about 2–3 seconds.
Laboratories use techniques such as spectroscopy, microscopy and luminescence under shortwave ultraviolet light to determine a diamond’s origin.[98] They also use specially made instruments to aid them in the identification process. Two screening instruments are the DiamondSure and the DiamondView, both produced by the DTC and marketed by the GIA.
Several methods for identifying synthetic diamonds can be performed, depending on the method of production and the color of the diamond. CVD diamonds can usually be identified by an orange fluorescence. D-J colored diamonds can be screened through the Swiss Gemmological Institute’s[101] Diamond Spotter. Stones in the D-Z color range can be examined through the DiamondSure UV/visible spectrometer, a tool developed by De Beers.[99] Similarly, natural diamonds usually have minor imperfections and flaws, such as inclusions of foreign material, that are not seen in synthetic diamonds.
Reference books for diamond
C. Even-Zohar (2007). From Mine to Mistress: Corporate Strategies and Government Policies in the International Diamond Industry (2nd ed.). Mining Journal Press.
G. Davies (1994). Properties and growth of diamond. INSPEC. ISBN 0-85296-875-2.
M. O’Donoghue, M (2006). Gems. Elsevier. ISBN 0-7506-5856-8.
M. O’Donoghue and L. Joyner (2003). Identification of gemstones. Great Britain: Butterworth-Heinemann. ISBN 0-7506-5512-7.
A. Feldman and L.H. Robins (1991). Applications of Diamond Films and Related Materials. Elsevier.
J.E. Field (1979). The Properties of Diamond. London: Academic Press. ISBN 0-12-255350-0.
J.E. Field (1992). The Properties of Natural and Synthetic Diamond. London: Academic Press. ISBN 0-12-255352-7.
W. Hershey (1940). The Book of Diamonds. Hearthside Press New York. ISBN 1-4179-7715-9.
S. Koizumi, C.E. Nebel and M. Nesladek (2008). Physics and Applications of CVD Diamond. Wiley VCH. ISBN 3-527-40801-0.
L.S. Pan and D.R. Kani (1995). Diamond: Electronic Properties and Applications. Kluwer Academic Publishers. ISBN 0-7923-9524-7.
Pagel-Theisen, Verena (2001). Diamond Grading ABC: the Manual. Antwerp: Rubin & Son. ISBN 3-9800434-6-0.
R.L. Radovic, P.M. Walker and P.A. Thrower (1965). Chemistry and physics of carbon: a series of advances. New York: Marcel Dekker. ISBN 0-8247-0987-X.
M. Tolkowsky (1919). Diamond Design: A Study of the Reflection and Refraction of Light in a Diamond. London: E. & F.N. Spon.
R.W. Wise (2003). Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones. Brunswick House Press.
A.M. Zaitsev (2001). Optical Properties of Diamond: A Data Handbook. Springer. ISBN 3-540-66582-X.
Source:
en.wikipedia.org/wiki/Diamond