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.
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.
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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
Diamond Criteria, Australian Standard Brochure