The presentation will touch upon defining and classifying optical and structural effects that add to a gemstone’s allure. Massi will address subjects of star rubies, the Usambara effect, chameleon diamonds, nomenclature of gemstone phenomena explaining aspects like alexandrite which has the ability to change color according to the type of light that illuminates it; asterism exhibited by gemstones such as star rubies and star sapphires display a 6- or 12-ray star that moves on the top of the stone when properly illuminated and cut as a cabochon; and that a chameleon diamond can reversibly turn from green to orange or yellow when placed in light or after gentle heating.
There will also be a discussion on optical and structural effects of gemstones studied through four broad categories: Color-change effects, Chatoyant effects resulting due to inclusions and the interaction of light, Asterism resulting from inclusions and the interaction of light and Other optical effects: such as iridescence, adularescence and aventurescence.
Massi holds a repute of presenting gemology lectures across the globe, has authored scientific and educational articles of which his recent one is based on the new gem mineral hibonite, one of the rarest gems on Earth featuring in GIA’s Gems & Gemology. Massi completed his PhD studies on ‘Atomic-scale defects in brown and hydrogen-rich diamonds’ and is a Graduate Gemologist.
The Gemstone Gathering is a free attendance event at the Crowne Plaza Hotel (formerly known as the Pan Pacific).
