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was cut too deep or shallow then light would escape out the sides or bottom of the diamond, resulting in a loss of brilliance (white light reflected up through the top of a diamond), fire (colored light reflected from within a diamond), and sparkle (combination of fire and brilliance).
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The original model was intended to be a set of general guidelines; several aspects of a diamond's cut had not been accounted for or explored. Later modifications of round brilliants differ in minor ways.
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Note that the thesis does not define the 'Tolkowsky cut', contrary to what is claimed in some third-party references, such as his NY Times obituary.
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Tolkowsky, as part of his PhD topic at the
University of London, systematically studied the grinding of diamonds. Around the same time, in his book
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Research on the
Abrading, Grinding or Polishing of Diamond, Thesis for the Degree of Doctor of Science (Engineering)
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Barak Green; Al
Gilbertson; Ilene Reinitz; Mary Johnson; James Shigley (14 September 2001).
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This biographical article about a
Belgian engineer, inventor or industrial designer is a
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22:(25 December 1899 – 10 February 1991), an engineer by education, was a
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Diamond Design: A Study of the
Reflection and Refraction of Light in a Diamond
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Diamond Design, A Study of the
Reflection and Refraction of Light in a Diamond
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107:"Marcel Tolkowsky, 92, A Retired Gemologist"
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209:"What did Marcel Tolkowsky Really Say?"
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