ABSTRACT
The amazing beauty and sparkle of a diamond, described and prized by many
novelists and poets, stems from much less poetic, yet superior properties of
diamond. These are primarily transparency and a high index of refraction
(Table 2.1). Other properties of diamond are less known, but not less important.
Some among them-high hardness (in fact the highest, 10 by the Moss scale),
chemical inertness, and high abrasion resistance are not without significance
for diamond jewels. However, these and especially some other properties-
thermal conductivity (again the highest), very low coefficient of thermal expan-
sion, very low coefficient of friction, very high electrical resistivity, high breaking
strength, and semiconducting properties of doped diamond are much more
important for other applications. At present, diamond is used mostly as a heat
sink, as an abrasive, and for advanced cutting tools. But, if it were not relatively
scarce in nature, other applications would certainly have been much more marked.
