Method and apparatus for examining an object
US5835200A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 1997 |
| Grant date | Nov 10, 1998 |
| Priority date | — |
| Expiry date | Feb 3, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/87
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In order to examine a gemstone, the stone is irradiated and observed though a filter (5) at a first wavelength which is characteristic of a first class of gemstones. The filter can be rocked from a setting normal to the optical axis to transmit radiation of at least one reference wavelength. The intensities of radiation transmitted at first and reference wavelengths are observed and compared, to classify the gemstone as belonging to the first class or not. In order to detect whether the gemstone is a diamond or diamond simulant, the first wavelength comprises raman emission characteristic of diamond. In order to detect whether the gemstone is definitely natural or not definitely natural, the gemstone is classified as definitely natural if there is a maximum of absorption of radiation at 415.5 nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.