Webinar Series

GIA Knowledge Sessions





The GIA Knowledge Sessions are a series of talks and seminars that engage participants in the most diverse and pressing issues in gemology today, including gemstone origin, laboratory-grown stones and new discoveries in field gemology. These webinars are brought to you by GIA Ph.D.s, field gemologists, educators and research scientists whose experience and expertise offer a trove of gem knowledge.

The sessions are free and open to the public. Registration in advance is required to attend.

Upcoming Sessions

Webinars in English

October 29, 2020 | Superstitions Surrounding Gems and Jewelry 
10:00 a.m. PDT
Speaker: Rose Tozer
Register Soon

Webinars in Mandarin

October 15, 2020 | Treatments in Corundum
9:00 p.m. HKT (6:00 a.m. PDT)
Speaker: Ziyin Sun
Register Soon

Past Sessions

Webinars in English

October 22, 2020 | Natural Blue Diamonds
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Natural blue diamonds are among the most valuable and famous of fancy color diamonds. From the Hope diamond with its fiery phosphorescence to hydrogen-rich diamonds with their intriguing Alexandrite effect, blue diamonds have always captured our imagination. Tune in as Dr. Sally Magaña – Sr. Manager of Diamond Identification – explores the science of blue diamonds and their close cousins, violet and gray diamonds, and delves into the stories of these legendary stones.

October 15, 2020 | Furnaces, Fluxes and Filling: A Review of Ruby Treatment
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Many gems are treated to improve their appearance. While treatments can be controversial, they help provide a market for a wide variety of qualities of natural gemstones, which helps keep the supply chain going. Ruby, the king of gemstones, is no exception in often being treated. The degree of treatment varies from none to minimal to a total make-over and can affect value accordingly. Follow GIA Supervisor of Field Gemology Wim Vertriest, as he explores common ruby treatments, their results and how to identify them.

October 8, 2020 | The Sapphires of Montana
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When the first prospectors set out for the American west, they were looking for gold, and in Montana they found their share. But some of these unwittingly lucky miners also found another dense precious mineral — sapphires. Most of the sapphires found in the 1800s in Montana were for industrial use. But in the late 1900s, heat treatment processes were developed that made Montana sapphires one of the most important American-mined gems. Join GIA researchers Nathan Renfro and Aaron Palke as they unearth the history and gemology of these stunning jewels.

October 1, 2020 | ​The Evolution of Laboratory-Grown Diamond Evaluation at GIA
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Both the quality and quantity of laboratory-grown diamonds have increased in the past several years. GIA’s reports for laboratory-grown diamonds have evolved as consumers’ knowledge and interest have grown. What has changed in the 14 years since GIA first started issuing reports for laboratory-grown diamonds? Discover the evolution of these man-made gems and learn about GIA’s new reports for laboratory-grown diamonds with Senior Research Scientist Mike Breeding.

September 24, 2020 | ​The History of Diamond Cutting and Polishing Technology
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Diamond is one of the hardest natural materials on earth, and cutting and polishing it is no simple feat. In recent decades, technological advancements such as laser cutting have greatly enhanced the ease and precision of diamond cutting, but artisans have been polishing diamonds since at least the end of the Middle Ages! How is it even possible to cut and polish this exceptionally hard material? How does human skill unleash a diamond’s brilliance? Learn the answers to these questions and more from GIA Research Scientist Dr. Evan Smith as he covers the history of diamond polishing and shares his own experience cutting diamonds for scientific research.

September 17, 2020 | ​Natural Pink Diamonds
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Natural pink to red diamonds are among the rarest and most desired fancy colored diamonds. How they form is still a mystery — but scientists have observed that the vast majority of pink diamonds have a 550 nm absorption band, which indicates that shear stress and deformation of the crystal structure had occurred while the diamond was deep within the earth. Tune in as Dr. Sally Magaña — Sr. Manager of Diamond Identification — dives into the science of pink and red diamonds and unravels the mysteries of these enchanting stones.

September 10, 2020 | ​A Comparison of Diamonds and Colored Stones: Geographic Origin to Geology and More
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Diamonds and colored stones are often considered to exist in entirely different realms in the gem and jewelry industry. This might partly be due to the fact that they are mined and brought to market so differently. Diamonds are primarily mined in large, industrial-scale operations, while colored stones such as rubies, sapphires and emeralds are typically produced by smaller-scale, often artisanal, operations. Their quality is also assessed very differently. Nonetheless, both diamonds and colored stones have helped scientists unlock secrets about Earth’s geology. Tune in as GIA Research Scientist Dr. Karen Smit and GIA Senior Manager of Research Dr. Aaron Palke reveal why these gems have more in common than you may have imagined.

September 3, 2020 | ​Natural Green Diamonds
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Naturally colored green diamonds are among the rarest of all colored diamonds. Unlike other diamonds that get their color deep in the earth, most green diamonds come into contact with radioactive fluids near the earth’s surface that create structural defects and produce their green color. Diamonds can also be turned green by irradiation treatment. Can natural green diamonds be separated from their treated counterparts? Unravel their mysteries with Senior Research Scientist Dr. Mike Breeding.

Aug 27, 2020 | ​Diving into the GIA 7 Pearl Value Factors™
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While diamonds have four primary areas of assessment (the 4Cs), pearls have seven! These include color, luster, nacre, surface and more. Evaluating pearl’s enchanting beauty can be quite complex. Did you know that in addition to bodycolor, some pearls also have overtone and orient? That’s why GIA has developed a systematic technique for evaluating pearls. Follow Senior Staff Gemologist (Pearls) Akira Hyatt as she explores the GIA 7 Pearl Value Factors and its recent updates, as well as introduces the new Cultured Pearl Classification Report.

Aug 20, 2020 | Glowing Diamonds: Fluorescence and Cathodoluminescence Imaging of Growth Structures and Defects​
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Did you know that roughly 35% of diamonds fluoresce or glow under longwave UV light? Besides longwave UV radiation, other methods can be used to “excite” diamonds so that even diamonds classified as non-fluorescent will glow. These methods are important to scientists, because a diamond’s glow can reveal unique and colorful growth patterns that help scientists separate natural diamonds from those that are laboratory-grown. Join us as Sr. Manager of Diamond Research, Dr. Ulrika D’Haenens-Johansson, shines a spotlight on the importance of fluorescence and cathodoluminescence in diamond identification and research.

Aug 13, 2020 | Russia’s Treasure of Diamonds and Precious Stones​
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GIA in Carlsbad houses perhaps the world’s most comprehensive collection of materials documenting the history, science, business and art of gems and jewelry. One of our most valuable works is Aleksander E. Fersman’s Russia’s Treasure of Diamonds and Precious Stones, bought by GIA in 1997. This rare historical catalog, created at the behest of the Soviet Union to help sell the Romanov family’s jewels, describes treasures such as the crown jewels and regalia of Russia. Follow Senior Research Librarian Rose Tozer as she opens the door to GIA’s archive and unlocks a trove of historical gem and jewelry knowledge.

Aug 6, 2020 | The Microworld of Gemstones
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The microscope is one of the most powerful instruments for analyzing gems. The inclusions contained within a gem as well as the features found on the surface can reveal a story about that gem. Get an up-close look at the microworld of gems with GIA Manager of Identification (Colored Stones), Nathan Renfro, and learn both standard and advanced microscopic techniques as well as the principals of lighting and photomicrography. This microscopic exploration is the beginning to uncovering the secrets hidden within the gemological microcosm.

July 30, 2020 | Diamond Ages: Are Diamonds Forever?
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Older than the dinosaurs and almost as old as Earth itself, diamonds are windows into the mysteries of our planet’s continuing geologic evolution. How old are the oldest diamonds and are diamonds still forming now? How are diamonds dated and why doesn’t carbon dating work on them? Join GIA Research Scientist Dr. Karen Smit and Senior Staff Scientist Dr. Steven Shirey of the Carnegie Institution for Science’s Earth and Planets Lab as they explore diamond dating and what diamonds teach us about the Earth.

July 23, 2020 | The Art of Photographing Minerals, Gemstones and Jewelry
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Robert Weldon, director of GIA’s library, has photographed some of the most extraordinary jewelry and gem specimens in the world. His work has graced the pages of “Splendour and Science of Pearls” and GIA’s scholarly journal, Gems & Gemology, to name just a few. Gems are known for the spectacular way they interact with light — glowing with color, sparkling or displaying fascinating phenomena. How do you capture their essence with a single shot? Peer through Robert Weldon’s camera lens as he talks tools, lighting, props and everything gemology.

July 16, 2020 | The Science Behind Fancy Color Diamonds
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Colored diamonds are priceless marvels of nature. From red and pink to green, blue, purple and brown, they exist in a rainbow of colors, caused by factors such as geologic forces, exposure to radioactive fluids or minerals, or atoms from trace elements being trapped in a diamond’s crystal lattice. Dazzled by these mysterious treasures? Tune in as Dr. Sally Eaton-Magaña — Sr. Manager of Diamond Identification — explores the science of diamond color and how fancy color diamonds are created within the earth.

July 9, 2020 | GIA Research Not Just for Scientists​
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Ever wonder who plans GIA courses and what goes into them? Gemology is part science, part art, part business. That’s why our education is fueled by GIA research — including our unique field gemology explorations — as well as informed by the information and experience of people throughout the industry. Whether you are a GIA alum or are simply curious about GIA education, tune in to “GIA Research — Not Just for Scientists” presented by Dr. Tao Hsu — Director of Global Professional Development — to get a behind-the-scenes look at how we design our world-respected curriculum.

July 2, 2020 | Geology 101 for Gemologists: The Natural Processes that Form Colored Gemstones
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What makes a gemstone rare and why are some gems rarer than others? The answer lies in gemstone geology. Some gems, such as emerald, require extraordinary geologic circumstances to form. Not only do different rock types need to meet under the right conditions and crystallize, certain rare elements often also need to be part of the mixture for the crystal to be the right color. Wim Vertriest, supervisor of field gemology, covers the chemistry of Earth’s crust and the geologic criteria for forming rubies, sapphires and some of the world’s most valuable gems.

June 25, 2020 | Diamond Color Treatment and Its Identification
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Natural fancy color diamonds acquire their color in a variety of ways, such as through trace elements, radiation and crystal lattice distortion. What about laboratory-grown fancy color diamonds? Or natural diamonds that have undergone treatment to change or improve their color? How are they created or treated and how do GIA scientists detect them? Tune in as Dr. Wuyi Wang, vice president of research and development, offers insight into diamond coloration, treatment techniques and the identification challenges facing gemologists today.

June 18, 2020 | Tools of the Trade: The Advanced Analytical Equipment Used in GIA Laboratories
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From loupes and microscopes to more advanced instrumentation, researchers use a host of tools to help them identify and analyze gems. Curious about how spectrometry helps scientists measure chemical impurities? Want to learn about laser ablation inductively coupled plasma mass spectrometry? Follow senior manager of research, Dr. Aaron Palke, on a behind-the-scenes tour of the tools used in a modern gemological laboratory, seeing with new eyes how scientists employ advanced analytical equipment to identify and characterize the gemstones that pass through GIA.

June 11, 2020 | Diamond Exploration & Mining
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Each year, mining companies invest hundreds of millions of dollars globally in finding new diamond deposits. Few of these explorations actually succeed. How do geologists decide where to look, what tools do they use to home in on diamonds and how do they know if they’ve discovered a commercially viable diamond mine? And once mining begins, what does diamond mining look like? GIA Research Scientist Dr. Evan Smith digs deeper into the process of unearthing these scintillating gems.

June 4, 2020 | An Overview on Pearl Identification: Techniques and Challenges
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The nacreous and non-nacreous layers that make up a pearl conceal many mysteries but also offer many clues to the gem’s origin — for those who can read them, that is. How do we know if a pearl is natural or cultured, saltwater or freshwater and what mollusk created it? Furthermore, how do we detect treatments especially on pearls' colors? GIA Manager of Pearl Identification Dr. Chunhui Zhou dives into pearl identification methods. From simple observation to x-ray radiography and DNA barcoding, learn how and why GIA scientists analyze these unique and lustrous treasures.

May 28, 2020 | Behind the Scenes: Untold Stories from GIA Field Gemology Expeditions
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GIA field gemologists journey far and wide to document gem geology and mining techniques. Behind their endeavors are moving stories, humorous anecdotes and fascinating local lore. Senior Manager of Research Dr. Aaron Palke, Supervisor of Field Gemology Wim Vertriest, and Director of the RTL Gemological Library Robert Weldon offer an exclusive look at GIA field gemology expeditions through previously unpublished photographs. 

May 21, 2020 | An Exclusive View of the Jade Auction
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Jadeite is the only colored gemstone whose auction price can rival that of ruby, emerald and sapphire. What is jadeite’s enduring appeal and what factors determine this gem’s value? Journey with Dr. Tao Hsu, geologist and director of global professional development for GIA education, as she explores a jadeite auction at the exclusive Myanma Gems Emporium in Myanmar — the country that produces over 90% of the world’s jadeite. Pick up insider tips and knowledge along the way!

May 14, 2020 | Laboratory-Grown Diamonds from China
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China is the world’s largest producer of laboratory-grown diamonds for industrial use and is now a significant producer of gem-quality laboratory-grown diamonds. What impact do Chinese laboratory-grown diamonds have on diamond prices and the jewelry industry? Find out as Dr. Wuyi Wang, GIA vice president of research and development, breaks down how and why laboratory-grown diamonds are produced in the world’s second-largest economy.

May 7, 2020 | Rubies: Connecting Sources, Treatment and Science
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Known as “the king of precious stones,” untreated rubies are some of the most valuable colored gems in the world. Find out why as Wim Vertriest, supervisor of field gemology at GIA Bangkok, explores the mining, treatment, lore and politics of these legendary gems.

April 30, 2020 | Fascinating World of Pearls and Shells
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We’re shelling out pearl knowledge with a webinar by Nick Sturman, senior manager of global pearl services at GIA. Do all bivalves, including oysters, clams and mussels, produce pearls? Which pearl types are the most popular and where are they found? Travel with us as we dive into the world of these rare organic treasures.

April 23, 2020 | GIA’s Field Gemology Program: A Research Based Approach to Origin Determination
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Senior manager of research, Aaron Palke, Ph.D., expounds on advanced research techniques to determine gemstone origin and how traceability may be the next challenge GIA undertakes.

April 16, 2020 | Laboratory-Grown Diamonds: Updates and Identification
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GIA senior research scientist, Dr. Mike Breeding, wants to tell you the story of laboratory-grown diamonds. If all diamonds are made of carbon, what separates laboratory-grown from natural?

April 9, 2020 | The Unique Story of Natural Diamond
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Research scientist, Dr. Evan Smith, explores the origin of natural diamonds and discusses their significance from the perspective of Earth science.

Webinars in Mandarin

September 17, 2020 | Laboratory-Grown Diamond Identification​
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In recent years, laboratory-grown diamonds have been produced in commercial quantities and qualities and are being used more and more in jewelry. Impossible to distinguish from natural diamonds with the unaided eye, laboratory-grown diamonds can only be detected through advanced analysis by a gemological lab. Tune in as GIA Vice President of Research and Development Wuyi Wang talks in-depth about laboratory-grown diamonds, including post-growth treatments and the identification methods used to detect these gems. 

August 20, 2020 | A Closer Look at Sapphire: Treatment and Geographic Origin​
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Sapphire has been cherished for thousands of years for its remarkable color, luster and hardness. What are the most popular modern treatment processes and how do they improve the appearance or durability of a sapphire? Where are sapphires mined and how do scientists track their provenance through inclusion study and advanced testing? Tune in as Jia Xiaodan, Senior Staff Gemologist of Colored Stones at GIA Hong Kong Laboratory, shares the most recent developments on sapphire treatments and origin determination.

August 6, 2020 | Major Gem Producing Areas Around the Globe​
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The world’s most productive gem sources are constantly changing. Old mines dry up while new ones are found. What are currently the most productive big three (ruby, emerald and sapphire) mines? Where are the best Paraiba tourmaline found? Fueled by data collected from 95 GIA field gemology expeditions to 21 countries, Director of Global Professional Development, Dr. Tao Hsu, offers an overview tour of the world’s most famed and productive gem sources.

July 23, 2020 | An Overview on Pearl Identification: Techniques and Challenges
Watch Webinar
The nacreous and non-nacreous layers that make up a pearl offer many clues to the gem’s origin. How do we know if a pearl is natural or cultured, saltwater or freshwater and what mollusk created it? Furthermore, how do we detect treatments? GIA Manager of Pearl Identification Dr. Chunhui Zhou dives into pearl identification methods. From simple observation to x-ray radiography and DNA barcoding, learn how and why GIA scientists analyze pearls.

July 9, 2020 | Advanced Analytical Techniques
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Gemology has come a long way as a field since its start in the early 1900s. Initially, gemology’s question was: “what is this stone?” Then: “is this stone laboratory-grown or natural?” and then “has this stone been treated?” Now, the all-consuming question is: “which country is this stone from?” As the industry evolves and our knowledge expands, so does our desire to learn more. That’s why advanced analytical techniques have become indispensable to modern gemology. Tune in as GIA research associate, Ziyin Sun, explores the instruments and techniques used to address gemology’s most pressing questions.

June 23, 2020 | The Fascinating World of Pearls and Shells
Watch Webinar
​We’re shelling out pearl knowledge with a webinar by GIA Manager of Pearl Identification Dr. Chunhui Zhou. Do all bivalves, including oysters, clams and mussels, produce pearls? What are conch and melo pearls? Which pearl types are the most popular and where are they found? From the seas of Australia, Tahiti and Thailand to the waters of China, travel with us as we dive into the world of these rare organic treasures.

June 11, 2020 | An Exclusive View of the World’s Biggest Jade Auction
Watch Webinar
Jadeite is the only colored gemstone whose auction price can rival that of ruby, emerald and sapphire. What is jadeite’s enduring appeal and what factors determine this gem’s value? Journey with Dr. Tao Hsu, geologist and director of global professional development for GIA education, as she explores a jadeite auction at the exclusive Myanma Gems Emporium in Myanmar — the country that produces over 90% of the world’s jadeite. Pick up insider tips and knowledge along the way!

May 28, 2020 | Laboratory-Grown Diamonds from China​
Watch Webinar
China is the world’s largest producer of laboratory-grown diamonds for industrial use and is now a significant producer of gem-quality laboratory-grown diamonds. What role does China play in the laboratory-grown diamond market and what impact does it have on the natural diamond market and the jewelry industry? Find out as Dr. Wuyi Wang, GIA vice president of research and development, breaks down how and why laboratory-grown diamonds are produced in the world’s second-largest economy.

Other GIA Virtual Events


Upcoming GIA Tokyo GemFests (Japanese)

October 9, 2020 | ​25th Tokyo GemFest: Advanced Analytical Equipment Used in GIA Laboratories
12:00 p.m. JST
Speaker: Dr. Yusuke Katsurada
Register Soon

October 15, 2020 | 26th Tokyo GemFest: Ethical and Sustainability of the Jewelry Industry
12:00 p.m. JST
Speaker: Shiraki Natsuko
Register Soon

Past GIA Tokyo GemFests (Japanese)

September 30, 2020 | ​24th Tokyo GemFest: Understanding CVD Diamond – Its History and Application
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Diamonds grown by chemical vapor deposition synthesis, known as CVD, are relatively new to the market and have attracted recent attenion. Japan developed CVD synthesis for diamonds in the early 1980s and has since been a global leader in CVD diamond research. In this seminar, Dr. Tsugawa, who been involved in CVD diamond research for years and currently works for the world-leading manufacturer of diamond CVD systems, will discuss the history and the current applications of CVD synthesis for diamonds.

August 19, 2020 | 23rd Tokyo GemFest: Extraterrestrial Gems: Attraction of Meteorites​
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Meteorites are visitors from space whose origins are asteroids. They formed 4.56 billion years ago when our solar system was born. Some rare meteorites came from the Moon and Mars. In this seminar, Dr. Mikouchi will talk about the attraction of meteorites from the viewpoints of their mineral beauty and the hidden history of the birth of the solar system and its evolution.

August 5, 2020 | 22nd Tokyo GemFest: Emeralds from the Ural Mountains​
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The Urals in Russia used to be the most productive emerald deposit in the 19th and early 20th centuries. Reviving emerald production in Mariinsky Priisk mine is bringing fine Russian emeralds back into the limelight. This seminar covers the geological background of emerald deposits and information from the GIA Field Gemology trip that the speaker joined in 2019.

July 8, 2020 | 21st Tokyo GemFest: Identification and Treatments of Colored Stones​
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The treatments of colored stones during the gem and jewelry trade process are carried out to improve the appearance and color of gemstones. Such treatments include heat treatments of ruby and sapphire, clarity enhancements of emerald, and a combination of bleaching and dying of jade. During this presentation, the types of colored stone treatments and identification methods will be introduced.

June 17, 2020 | 20th Tokyo GemFest: Geographic Origin Determination of Ruby
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Ruby is produced in a variety of localities, ranging from Southeast and Central Asia (including Myanmar), to East Africa. This seminar will introduce GIA's efforts in geographic origin determination and will share the latest findings on rubies.

May 29, 2020 | 19th Tokyo GemFest: Geographic Origin Determination of Paraíba Tourmaline​
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Blue to green copper-bearing tourmaline, known as Paraíba Tourmaline, has been quite popular in the colored gemstone market for the past three decades. This seminar will review its gemological characteristics and discuss GIA’s geographical origin determination.

May 21, 2020 | 18th Tokyo GemFest: Laboratory-Grown Diamonds Basics and Updates​
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Recently, we are seeing an increase in laboratory-grown diamonds used in jewelry. In this seminar, we explain the synthesis methods and the characteristics of laboratory-grown diamonds that are useful for identification. We also introduce some of the latest laboratory-grown diamonds examined at GIA.

May 8, 2020 | 17th Tokyo GemFest: Gemological Characteristics and Origin Identification of Alexandrite​
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Alexandrite is a famous gemstone that shows a beautiful color change effect. In this seminar, we introduce the basic gemological characteristics of alexandrite and GIA’s Identification and Origin Report service which started in early 2019.

Past GIA Gemstone Gatherings

September 23, 2020 | Traditional vs. Non Traditional Color Terms Applied to Sapphires
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Over the past five years, the sapphire market has seen an uptick in demand for two hue ranges seen in sapphires — rO-oY(peach) and bG-gB (teal). This session will give attendees the tools to understand and articulate clearly to their customers the subtle differences between pinkish-orange, orangish pink, and Padparadscha stones. Sheahan will also give clear-cut descriptions for G (green), bG-gB (teal), and yellow-green sapphires. Through reviewing a number of graphs covering time, color, consumption, and shifting prices, attendees will gain an in-depth understanding of what’s causing this movement toward fancy-colored sapphires from traditional blue stones. Ultimately, this session will help attendees understand their customers’ requests/needs more clearly and help them close sales on these unique, fancy-colored sapphires.

June 24, 2020 | 115th Gemstone Gathering: Precision Cut: How, Why and When?
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The expression “precision cut” has become very popular over time. Victor Tuzlukov will explain his point of view on the term "precision cut" and share his inspirations that led him to become a professional cutter. He will also lead a discussion on the advantages and disadvantages of the precision cut, how such lapidary work affects the gemologist, and how to judge whether existing fashioned stones would benefit from re-cutting.

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