Diamond separation process
AssigneeThe British Petroleum Company p.l.c.
InventorsHeather J. Bowley, Donald L. Gerrard
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Abstract
A method of assessing the color type of diamonds by irradiating the diamonds with laser radiation of different wavelengths and generating a numerical value characteristic of the color type of the diamond based on the measured intensities of the resultant scattered Raman radiation for two or more different incident radiation wavelengths. The color type of the diamond may be determined by comparing derived relative intensities of each diamond with those of reference diamonds having been determined by standard subjective assessment. The method may also be used to sort diamonds according to their color type.
Claims13
A method of assessing the colour type of diamonds comprising the steps of (a) passing incident laser radiation of pre-determined intensity at two or more different, pre-determined wavelengths onto a diamond, the laser radiation being capable of causing Raman radiation to be scattered from the diamond, (b) measuring the intensity of the scattered Raman radiation from the diamond for each of the incident laser radiation wavelengths, (c) generating a numerical value characteristic of the colour type of the diamond based on the measured intensities of scattered Raman radiation for the two or more different incident laser radiation wavelengths.
An apparatus for assessing the colour type of diamonds comprising, (a) means for irradiating a diamond with laser radiation of pre-determined intensity at two or more different, pre-determined wavelengths, the laser radiation being capable of causing Raman radiation to be scattered from the diamond, (b) means for measuring the intensity of the scattered Raman radiation from the diamond for each of the incident laser radiation wavelengths, (c) means for generating a numerical valve characteristic of the colour type of the diamond based on the intensities of scattered Raman radiation for the two or more different laser radiation wavelengths.
A method of determining the colour type of diamonds comprising the steps of (a) passing incident laser radiation of pre-determined intensity at two or more different, pre-determined wavelengths onto a diamond, the laser radiation being capable of causing Raman radiation to be scattered from the diamond, (b) measuring the intensity of the scattered Raman radiation from the diamond for each of the incident laser radiation wavelengths, (c) generating a numerical value characteristic of the colour type of the diamond based on the measured intensities of scattered Raman radiation for the two or more different incident laser radiation wavelengths, (d) comparing the numerical value with numerical values of diamonds of known colour type thereby to determine the colour type of the diamond.
A method of sorting diamonds according to their colour type comprising (a) passing incident laser radiation of pre-determined intensity at two or more different, pre-determined wavelengths onto a diamond, the laser radiation being capable of causing Raman radiation to be scattered from the diamond, (b) measuring the intensity of the scattered Raman radiation from the diamond for each of the incident laser radiation wavelengths, (c) generating a numerical value characteristic of the colour type of the diamond based on the measured intensities of scattered Raman radiation for the two or more different incident laser radiation wavelengths, (d) sorting the diamond according to the generated numerical value.
Dependencies are inferred from the claim text.