Analysis Of Gem-Quality And Experimental Estimation Of Toleration Ranges In Geometrical Features Of Brilliant Type Cut Diamonds
ABSTRACT
The measures that influence the quality of diamonds are cut, shape, colour, clarity and weight. These features are therefore of some economic significance. It has long been recognized that similar type diamonds with identical cuts are subject to some variability in geometrical features that can give rise to differences in their quality. In the present study a brief review is presented of previous investigations that looked at properties of diamonds. This is followed by an overview of current practices in estimating the quality of diamonds with particular focus on brilliant type cut diamonds. The results are presented with prominent dimensional features, namely, girdle diameter, table, crown, girdle width, pavilion and their corresponding angles that were measured on 12 stones, six in each of 2 sets, ‘as bought’ brilliant type cut diamonds from one supplier. Variations in scatter and the mean value of each dimensional feature between the two sets of diamonds were estimated using relevant statistical methods. The results are discussed in the paper from both a qualitative and a quantitative point of view. It is suggested that this sort of information may be used to assist in assessing the quality of brilliants and selecting geometrically similar stones for jewels, when needed.
The measures that influence the quality of diamonds are cut, shape, colour, clarity and weight. These features are therefore of some economic significance. It has long been recognized that similar type diamonds with identical cuts are subject to some variability in geometrical features that can give rise to differences in their quality. In the present study a brief review is presented of previous investigations that looked at properties of diamonds. This is followed by an overview of current practices in estimating the quality of diamonds with particular focus on brilliant type cut diamonds. The results are presented with prominent dimensional features, namely, girdle diameter, table, crown, girdle width, pavilion and their corresponding angles that were measured on 12 stones, six in each of 2 sets, ‘as bought’ brilliant type cut diamonds from one supplier. Variations in scatter and the mean value of each dimensional feature between the two sets of diamonds were estimated using relevant statistical methods. The results are discussed in the paper from both a qualitative and a quantitative point of view. It is suggested that this sort of information may be used to assist in assessing the quality of brilliants and selecting geometrically similar stones for jewels, when needed.
KEYWORDS
Diamonds, Brilliant Type Cuts, Statistical Analyses, Similarities and Differences, Gem Quality
Diamonds, Brilliant Type Cuts, Statistical Analyses, Similarities and Differences, Gem Quality
Cite this paper
J. Audy, K. Audy and T. Haines, "Analysis Of Gem-Quality And Experimental Estimation Of Toleration Ranges In Geometrical Features Of Brilliant Type Cut Diamonds," Journal of Minerals and Materials Characterization and Engineering, Vol. 4 No. 2, 2005, pp. 95-106. doi: 10.4236/jmmce.2005.42009.
J. Audy, K. Audy and T. Haines, "Analysis Of Gem-Quality And Experimental Estimation Of Toleration Ranges In Geometrical Features Of Brilliant Type Cut Diamonds," Journal of Minerals and Materials Characterization and Engineering, Vol. 4 No. 2, 2005, pp. 95-106. doi: 10.4236/jmmce.2005.42009.
References
[1] Callister W.D.Jr.: “Fundamentals of Materials Science and Engineering: An Integrated Approach”, 2nd Edition, John Wiley & Sons, Inc., ISBN 0-471-47014-7, USA, 2005, p. 219 [2] Funk and Wagnalls: “Encyclopedia”, 1973, Library of Congress Catalog Card Number 72-170933, USA, Volume 7, p. 462. [3] Snell F.D. and Ettre L.S.: “Encyclopedia of Industrial Chemical Analysis”, Volume 11, John Willey and Sons Inc., Catalogue Card Number 65-27477, USA, pp.462 to 474. [4] Collins A.T.: “Improving the Colour of Gem-Quality Diamonds by High Pressure, High Temperature Annealing”, Materials Today, Elsevier, ISSN: 1396-7021, Vol.3 Issue 3, 2000, pp. 3 to 6. [5] National Geographic, “Diamonds, The Real Story”, Vol. 201. No. 3, March 2002 [6] Lazare Diamonds The Ideal Cut, Larry Jewelry, Singapore, Paragon Ngee Ann CityTower Raffles City Shopping Centre, tel: (65) 732 3222, or 235 5848, or 336 9648 [7] Diamond Criteria, Australian Standard Brochure
[1] Callister W.D.Jr.: “Fundamentals of Materials Science and Engineering: An Integrated Approach”, 2nd Edition, John Wiley & Sons, Inc., ISBN 0-471-47014-7, USA, 2005, p. 219 [2] Funk and Wagnalls: “Encyclopedia”, 1973, Library of Congress Catalog Card Number 72-170933, USA, Volume 7, p. 462. [3] Snell F.D. and Ettre L.S.: “Encyclopedia of Industrial Chemical Analysis”, Volume 11, John Willey and Sons Inc., Catalogue Card Number 65-27477, USA, pp.462 to 474. [4] Collins A.T.: “Improving the Colour of Gem-Quality Diamonds by High Pressure, High Temperature Annealing”, Materials Today, Elsevier, ISSN: 1396-7021, Vol.3 Issue 3, 2000, pp. 3 to 6. [5] National Geographic, “Diamonds, The Real Story”, Vol. 201. No. 3, March 2002 [6] Lazare Diamonds The Ideal Cut, Larry Jewelry, Singapore, Paragon Ngee Ann CityTower Raffles City Shopping Centre, tel: (65) 732 3222, or 235 5848, or 336 9648 [7] Diamond Criteria, Australian Standard Brochure