OGI Scanner — Automated Gemstone Measurement and Proportion Analysis
OGI Scanner — Automated Gemstone Measurement and Proportion Analysis
Digital instruments from OGI Systems used to capture proportions, symmetry, and dimensions of polished diamonds and coloured stones
The OGI scanner is an automated gemstone-measuring instrument manufactured by OGI Systems, with the OGI Megascope being the best-known model. The scanner captures digital images of the stone from multiple angles and calculates proportions, symmetry, dimensions, and other geometric properties of polished diamonds and coloured gemstones. The instrument is widely used by laboratories, dealers, and manufacturers for quality control, grading support, and inventory documentation, providing repeatable measurements that reduce subjectivity in cut-quality assessment.
How it works
The scanner operates by placing the stone on a rotating stage within an enclosed measurement chamber. Cameras and lighting systems capture images of the stone from multiple angles as it rotates, and onboard software processes the images to extract dimensional and geometric data. The output includes table size, crown height, pavilion depth, girdle thickness, total depth, and various symmetry parameters, along with proportion diagrams and reports.
For round brilliant diamonds, the scanner can produce GIA-style proportion diagrams and key measurements that support cut-quality grading. For coloured stones, the scanner provides dimensions and proportions that allow standardised comparison and documentation. Modern OGI instruments can also estimate weight from dimensions, supporting verification against scale weight, and can capture images for inventory and reporting purposes.
Use cases
OGI scanners are used by major laboratories as part of their grading workflow, particularly for cut-quality assessment of round brilliant diamonds. The automated, repeatable measurements provide an objective baseline that complements the visual assessment of trained graders. Manufacturers use the scanners for production quality control, ensuring that finished stones meet specification before they leave the cutting floor.
Dealers use scanners for inventory documentation and for verification of stones offered by suppliers. The repeatable measurements provide a check against weight and dimension claims, and the captured images can be used in trade-level documentation. For higher-value stones, OGI scans complement laboratory reports rather than substituting for them.
Position in the laboratory and trade ecosystem
Several manufacturers produce automated gemstone-measuring instruments — Sarine, Imagem, and others — with overlapping but distinct feature sets. The choice among these instruments depends on the specific use case (laboratory grading vs. trade inventory vs. manufacturing QC), the volumes processed, and the integration with broader software systems. OGI Systems has historically been a strong choice for diamond-focused operations, with broad adoption among laboratories and large diamond manufacturers.