DDG Ass 19 Key Terms & Concepts PDF

DDG Ass #19 Key Terms & Concepts Aperture—Opening through which light enters a camera. Diamantaire—A knowledgeable, experienced professional, typically a dealer or manufacturer, in the diamond trade. Exposure—The amount of time light has to enter a camera. Matching Tray—A grooved whi...

DDG Ass #19 Key Terms & Concepts Aperture—Opening through which light enters a camera. Diamantaire—A knowledgeable, experienced professional, typically a dealer or manufacturer, in the diamond trade. Exposure—The amount of time light has to enter a camera. Matching Tray—A grooved white non-reflective tray used for matching sets of stones. Photoluminescence Mapping—A spectroscopy technique that collects PL data across the entire surface of a diamond, showing subtle distinctions in defect concentrations. Scoop—A small shovel made of thin metal, used for picking up gems. Sieve Set—Set of circular plates, each punched with precisely sized holes, used for sorting small, round gems by size. Sorting Pad—A pad of white paper for sorting and showing gems. Spectrometer—A highly sensitive instrument that analyzes a gem’s radiation absorption. Stone Paper—A folded paper that comes in standard sizes used to hold and protect diamonds, as well as organize diamond inventory. Key Concepts: Electronic scales are extremely accurate, but they must be set up correctly for best results. The information gathered with advanced instrumentation can help conclusively identify a diamond. Advanced testing results require further interpretation by experienced laboratory gemologists. A UV-Vis-NIR spectrometer measures a diamond’s absorption of visible light and portions of the ultraviolet and infrared regions close to the visible range. UV-Vis-NIR absorption spectroscopy is vital for colored diamond identification. Fourier-transform infrared (FTIR) spectroscopy measures a diamond’s absorption of infrared energy. The presence or absence of absorption caused by boron and/or nitrogen within a diamond's infrared spectrum—and whether the nitrogen is isolated or aggregated—determines its diamond type. Photoluminescence spectroscopy allows for extremely precise detection of trace concentrations of defects, which is unmatched by other nondestructive characterization techniques. Photoluminescence spectroscopy examines light emitted by a diamond after exposure to a high-power laser. While most diamonds do not fluoresce to shortwave or longwave UV, all diamonds show fluorescence at the ultra-shortwave UV wavelength. The DiamondView imaging microscope operates at a lower wavelength and higher energy than the ultraviolet light typically used for fluorescence observations in routine gemological work. The DiamondView is a reliable tool for identifying HPHT and CVD lab-grown diamonds.