|DIAGNOSTICS OF CUT DIAMONDS AND DISTINGUISHING THEM FROM IMITATIONS|
Diagnostics of cut diamonds implies successive diagnostic tests and comparison between the properties of the sample under study with those of diamond and its imitations (Table 2). The diagnostics results in concluding whether the sample is a diamond or an imitation. All the diagnostic methods are divided into primary and secondary ones. The primary diagnostic methods are most common and provide quick diagnostics. To make the diagnostics unambiguous, it is necessary to successively run several tests based on measuring the following physical properties of the studied sample: heat conductivity, refractivity, optic character (singly refractive or doubly refractive), and specific gravity.
The secondary diagnostic methods are used in those cases when the results of the primary diagnostic methods do not allow a gemologist to make an unambiguous conclusion or when it is desirable to additionally check these results.
A cut gemstone to identify should have a clean surface. To avoid soiling the stone, it is recommended to handle it with tweezers while running the diagnostic tests.
Diamond has the following distinctive features: