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The double cone fracture in flint

Published online by Cambridge University Press:  01 May 2009

D. J. Williams
D. J. Williams
Affiliation:
University of Cambridge, Department of Engineering, Trumpington Street, Cambridge CB2 1PZ
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Summary

This work proposes a mechanism for the formation of the characteristic ‘double cone’ cracking and ‘bulb of percussion with bulbar scar’ cracking caused by the artificial fracture of flint. The double cone fracture is observed as a large, small apex angle, cone that is truncated by a smaller cone of increased apex angle. The author considers that the large narrow apex angle truncated cone of the fracture is caused by Hertzian loading of the flint on impact and the upper complete cone is formed as a result of the unloading of the stressed flint. This mechanism has been deduced from work carried out in the fractography of glass by others and from some restricted laboratory experiments.

Type
Articles
Information
Geological Magazine , Volume 120 , Issue 3 , May 1983 , pp. 291 - 294
Copyright
Copyright © Cambridge University Press 1983

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References

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