Our planet's supply of diamonds were produced by four different processes. One took over a million years to achieve results. The next have been working in laboratories and factories, with increasing success, since the 1950s. But until this month man had never replicated that final process.
Jewelers of America and IGI are pleased to present an educational webinar at 2:00 PM Eastern Time Wednesday December 2. Learn physical differences, distinctive characteristics and quality-factors attributable to growth methods and timelines.
Following a similar benchmark set three months ago, IGI Hong Kong recently certified the largest laboratory-grown diamond received to date. With a finished weight of 12.75 carats, this collection-quality man-made gemstone was fashioned from a staggering 46.20 carat CVD-grown rough crystal
Today we turn our attention to the optical phenomenon of iridescence, that is the display of dispersive prismatic colors caused by the interference of light - generally due to thin films of gas or liquid - like Iridescent Quartz, Iridescent Agate and Ammolite.
Hearts & Arrows (H&A) diamonds are precisely cut to show kaleidoscopic patterns when seen in a special reflective viewer. Typically associated with Excellent-Ideal cuts of superior quality, fashioning the highest levels of H&A optical precision when working with the world's hardest substance is an exacting process.
This 10+ carat HPHT produced lab-grown diamond was initially graded Fancy Intense Yellow by IGI. When it returned to the lab its color had been changed to Fancy Vivid Pink. IGI confirmed that the color had been shifted from yellow to pink through irradiation using a 5MeV Electron Beam Transfer system.
Treatments have been used to enhance the appearance of gemstones since ancient times. The Egyptians, Greeks and Romans used dyes, coatings, oils and other methods to improve the color, durability and luster of their gemstones and pearls. But the most fascinating and fanciful tool used for enhancements may very well be the humble chicken.
Gemstones and fancy-colored-diamonds appear in all the colors of the rainbow, at different shades, with different intensities. Since the human eye can distinguish around 13 million shades and nuances of color, gemologists have developed a consistent method of mapping a gemstone's proper position in the broad 'Color Universe.'