Conventional shape measurement – visual evaluation standards show limitations

While the visual inspection method has been a viable and valuable means of guaranteeing product shape quality, it is a qualitative, rather than quantitative means of measuring diamond shape.

Diamond Shape Standard
Diamond shapes can range from the well structured cubo-octahedral morphology shown above to partially grown, irregular and fragmented crystals.

Computerized Image Analyses

• Improves sorting and classification of diamonds
• Enables us to test and match specific shapes to specific applications

Diamond Innovations developed an entirely new shape measuring technique for diamonds. Image analysis techniques from interpreting satellite photographs, were successfully adapted to measure diamond crystal morphology.

The system includes an optical imaging setup to capture diamond images and software packages to fit shape models to actual crystals. A combination of conventional image analyses parameters and a unique, DI invented diamond shape parameter, called “tau” are used to characterize the shape of saw diamond products.

Unique diamond shape parameter “tau” – invented by Diamond Innovations

Regular diamond crystal morphology falls between a near cube “I” and an octahedron “A”. Shapes ranging between these two morphologies are combinations of cubic and octahedral faces. The “tau” parameter is a rigorous continuous measure of this shape range where a cube has a tau of 1.0 and an octahedron has a tau of 0.0.

To measure the tau of a diamond sample the image analysis system fits a template to the inner and outer outline of the diamond crystal image. These templates are established by a complex series of algorithms in our patented diamond shape analysis software. Tau became a unique means of measuring product shapes for the highest grades of saw diamond: good, whole cubo-octahedral crystal shapes.

The Image Analysis System of Diamond Innovations uses a unique diamond modeling parameter called “tau“ to measure crystal shapes. Tau measures an octahedron as 0.0 and a cube as 1.0. Diamond shapes in between have a measurement within this range.

The Image Analysis System uses a complex series of algorithms to fit a template to the inner and outer outline of a diamond crystal image in a two-dimensional view.

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