Five Don’t-Miss Hands-On Sessions with GIA

Conclave isn’t complete without experiencing one of GIA’s hands-on sessions! This is your opportunity to learn from some of GIA’s top gemology experts and research scientists about the country of origin determination for emeralds, rubies, and sapphires, and about one of the most underappreciated gemstones—spinel.

Take a look at these terrific sessions taught by Aaron Palke, Senior Research Scientist, GIA Colored Stone Identification, and Nathan Renfro, Manager of Identification (Colored Stones) at GIA.

Aaron Palke
Nathan Renfro
Nathan Renfro

Sunday, September 12 / 9:00 a.m.–11:00 a.m. / State Room 3

GIA Hands-On: Country of Origin Determination – Emerald
Aaron Palke

In the modern-colored stone trade, country of origin has become one of the most important value factors in addition to color, size, and clarity. This is especially true for the high-end colored stone trade, since certain origins can dramatically increase the value of the stones while others do not.

For centuries, the global emerald trade was dominated by one source—Colombia. However, the expansion of gemstone mining in the modern era brought many more emerald sources to the world. With this diversification in global emerald sources came the potential for more overlap in the gemological characteristic of emeralds from different geographic locales. This seminar will provide an insider’s view of the scientific approach taken in the modern gem lab for emerald country of origin determination.

This seminar will be led by a senior GIA research scientist with hands-on experience. After taking this seminar, you will be able to identify the main emerald sources around the globe and the microscopic features that are characteristic for each. You will familiarize yourself with the advanced testing modern gem laboratories use to help determine country of origin for emerald. The instructor will also address the complications and challenges involved in emerald country of origin determination.

Sunday, September 12 / 2:30 p.m.–4:30 p.m. / State Room 3
Monday, September 13 / 3:00 p.m.–5:00 p.m. / State Room 3

GIA Hands-On: The Microworld of Spinel
Nathan Renfro

Spinel has long been an underappreciated gem, often placed in the shadows of its traditionally more expensive gemstone cousin, the ruby. Historically, red spinel was visually mistaken for ruby before being acknowledged as its own mineral species, the most notable being the Black Prince’s ruby which adorns the Imperial State Crown on display in London. In recent years, spinel has seen a significant rise in popularity and is recognized as one of three birthstones for August.

Spinel’s appeal may be due in part to its range of colors, from red to pink, purple, blue, gray, and orange. Myanmar, Pakistan, Sri Lanka, Tanzania, and Tajikistan are all notable sources of gem spinel. Inclusions found in spinel often reflect the geologic conditions in which they form. Some inclusions can cause asterism in spinel. Treatments for spinel are generally few and rarely leave evidence seen in the microscope. Synthetic spinels created by various techniques are commonly encountered in the trade.

In this seminar, you will be able to look at a wide range of inclusions found in spinel. The instructor will guide through the characteristics of these inclusions and their meaning in gemology.

Monday, September 13 / 10:15 a.m.–12:15 p.m. / State Room 3

GIA Hands-On: Country of Origin Determination – Ruby
Aaron Palke

In addition to color, size, clarity and carat weight, country of origin is another important value factor for colored gemstones. This is especially true for high-end colored stones trade, since certain origins can dramatically increase the value of the stones while others do not.

Ruby, as the king of colored stones, fetches some of the highest prices of all gems. Just about a century ago, rubies were mined only in a handful of sources. Over the past half a century, more ruby sources were discovered. Among all sources, some carry more legends, romance and even high quality as their status quo. Therefore, a reliable and science-based country of origin determination call became more important than ever before. State of art gem laboratories use traceable sample collection, advanced testing in combination with decades of accumulated experience from the well-trained gemologists to make the calls.

This seminar will be led by a senior GIA research scientist with hands-on experience. After taking this seminar, you will be able to Identify the main ruby sources around the globe and the microscopic features that are characteristic for each. You will also familiarize yourself with the advanced testing modern gem laboratories use to help determine country of origin for ruby. At the same time, the instructor will address the complications and challenges involved in ruby country of origin determination.

Tuesday, September 14 / 10:15 a.m.–12:15 p.m. / State Room 3

GIA Hands-On: Country of Origin Determination – Sapphire
Aaron Palke

Country of origin is the most important value factor for colored gemstones in addition to the quality factors of the stones themselves. This is especially true for high-end colored stones trade, since certain origins can dramatically increase the value of the stones while others do not.

The pressing issue of country origin determination is especially challenging for blue sapphire. This seminar will introduce to you the main sapphire sources around the globe and their status in the market. Due to significant overlap of the inclusion scenes for sapphire from multiple sources, trace element analyses and spectroscopic tests are applied to facilitate the country of origin determination.

This seminar will be led by a senior GIA research scientist with hands-on experience. After taking this seminar, you will be able to identify the main sapphire sources around the globe and the microscopic features that are characteristic for each. You will also familiarize yourself with the advanced testing modern gem laboratories use to help determine country of origin for sapphire. The instructor will also address the complications and challenges involved in sapphire country of origin determination.