NCJ Number
174928
Journal
International Journal of Forensic Document Examiners Volume: 3 Issue: 1 Dated: January-March 1997 Pages: 68-73
Date Published
1997
Length
6 pages
Annotation
The analysis of microscopic differences in markings made by various graphites on paper can be used as a rapid method of determining the purity and characteristics of a graphite sample.
Abstract
he author has now used this method to examine other types of graphite and has compared the findings with the results of chemical analyses of the graphites. The samples include graphite from Cornwall, England; graphite from ancient Egypt; compressed graphites, early metallic pencil markings from England; and composite pencil pigments. The analyses revealed that the points of distinction in blacklead pigments are the color-tone and arrangement of the pigment, the quantity and appearance of silver striations, and various chemical differences. Analyses have also focused on pencils with red and blue pencils. Determining which of two intersecting lines was written first is often possible in samples involving blacklead pencils due to the sequence of silver striations; cases involving color pencils require the removal of the soluble part of the pigment and do not always permit definite conclusions. Tables and discussion