Abstract: An assembly is provided comprising a gemstone holder and a battery housing. The gemstone holder comprises a bezel portion providing a mount for receiving a gemstone and a shaft portion comprising an elongate shaft. The elongate shaft comprises first and second electrically conducting portions. The battery housing comprises a battery power source and a plurality of apertures, the first one of said plurality of apertures being configured to enable engagement of an end portion of the shaft with a first connector within the housing, and the second one of said plurality of apertures being configured to enable engagement of an end portion of the shaft with a second connector within the housing. The assembly further comprises a light emitting diode, LED, configured to illuminate the gemstone.

Abstract: A method and apparatus for orientating discrete objects, such as gemstones, is described. The method comprises providing the objects on a travelling path; providing a pair of opposed walls (38) extending generally along the direction of the path; and generating relative oscillatory movement (14) between the pair of walls (38) and the travelling path (in a direction generally transverse to the direction of the path), so that the pair of walls (38) imparts lateral force to the objects to thereby urge them into their most stable orientation as they progress along the path. A device for checking the orientation of the discrete objects is also described.

Abstract: A method and apparatus for generating a 3D model of and/or detecting inclusions in a polished gemstone such as diamond is described. The gemstone (103) is rotated in a series of discrete increments. At each rotational position of the gemstone, the gemstone (103) is illuminated with collimated light (111,112) and a silhouette image recorded. At each rotational position, the gemstone (103) is also (before further rotation) illuminated with diffuse light (109), and a diffuse image recorded. The images are analyzed to obtain a 3D model of the surface of the gemstone. Features may then be identified in the diffuse images and tracked between subsequent diffuse images. The tracked features may be located relative to the 3D model of the gemstone, taking into account reflection and refraction of light rays by the gemstone. Some or all of the located features may then be identified as inclusions.

Abstract: A method and apparatus for orientating discrete objects, such as gemstones, is described. The method comprises providing the objects on a travelling path; providing a pair of opposed walls (38) extending generally along the direction of the path; and generating relative oscillatory movement (14) between the pair of walls (38) and the travelling path (in a direction generally transverse to the direction of the path), so that the pair of walls (38) imparts lateral force to the objects to thereby urge them into their most stable orientation as they progress along the path. A device for checking the orientation of the discrete objects is also described.

Abstract: A method and apparatus for generating a 3D model of and/or detecting inclusions in a polished gemstone such as diamond is described. The gemstone (103) is rotated in a series of discrete increments. At each rotational position of the gemstone, the gemstone (103) is illuminated with collimated light (111,112) and a silhouette image recorded. At each rotational position, the gemstone (103) is also (before further rotation) illuminated with diffuse light (109), and a diffuse image recorded. The images are analysed to obtain a 3D model of the surface of the gemstone. Features may then be identified in the diffuse images and tracked between subsequent diffuse images. The tracked features may be located relative to the 3D model of the gemstone, taking into account reflection and refraction of light rays by the gemstone. Some or all of the located features may then be identified as inclusions.

Abstract: An invisible information mark is provided on a facet of a diamond gemstone by applying a plasma resist to the exposed surface of the gemstone, applying an electrically conducting layer of metal to the region where the information mark is to be formed, ablating a selected zone of the metal and resist layers by ultraviolet laser thus forming a mask on the surface of the facet, electrically connecting the metal layer and plasma etching the facet through the mask, thus forming a mark of appropriate depth on the surface of the gemstone.