Fluorescence is one of the most powerful tools for determining a diamond’s identity. Deep-UV fluorescence patterns in natural diamonds (seen here) help GIA researchers separate them from laboratory-grown diamonds. How? These patterns tell about their formation conditions, time in the mantle, and transportation to Earth’s surface. Some of these processes include: - Natural diamonds, supplied with carbon atoms while deep in the Earth’s mantle, grow outward from a nucleating core. - They can go through periods when they are attacked by aggressive fluids that remove atoms and lead to crystal dissolution and resorption. - Diamonds also form defects due to distortion of their crystal structure from high pressure in the mantle. Since many of the above diamond defects are luminescent, these telltale signs can be observed through fluorescence and phosphorescence. Editor note: Nearly all diamonds fluoresce at deep UV wavelengths -- even if the grading report shows as None for long-wave UV. Read the full article in the latest G&G issue to learn what fluorescence tells us about diamonds: https://www.gia.edu/gems-gemology/winter-2024-fluorescence-phosphorescence?utm_campaign=g-g&utm_content=1747889700&utm_medium=organic-social&utm_source=facebook (fb)

Where in the world do emeralds come from? 🌎 Some major emerald-producing countries include: - Colombia: The most important emerald source in the world, Colombia is known for its large, fluorescent, intense green emeralds. It produced the 75.47-carat Hooker emerald, the 37.80-carat Chalk emerald, and the emeralds set in the Crown of the Andes. - Zambia: The second largest source of emeralds, Zambia is known for its high-clarity emeralds with higher iron content. Zambia produced the Insofu emerald, a 6,255-carat emerald crystal transformed into an entire jewelry line by Chopard. - Brazil: Brazil is another important source for emeralds. The most famous emeralds from Brazil include the 180,000-carat (836-pound) Bahia emerald crystal and the 1,385.95-carat Duke of Devonshire emerald crystal. - Afghanistan: Emeralds from the Panjshir Valley are known for their dark green color and high clarity. Their geological origin is more similar to Colombian emeralds than typical schist hosted emeralds in Zambia. Afghanistan is considered a historic source of fine emeralds. Learn more about emerald origins on our website: https://bit.ly/44NGT48 Photos courtesy: Vincent Pardieu (fb)