2009 GIA Gem Gathering Bangkok :

Meteorites: Heavenly Jewels

2009 GIA Gem Gathering Bangkok:

Trapiche: The Rising Star

2010 GIA Gem Gathering Bangkok

Opal: Still the Queen of Gems

2011 GIA Gem Gathering Bangkok:

 Spinel: The Great Impostor

2011 GIA Alumni Assn. Atlanta, Georgia – Spinel: The Great Impostor

2012 World of Gems Conference III Chicago: Hexagonal geometry in art, architecture, religion, biology, minerals, gemstones and jewelry

2012 GIA Alumni Assn. San Francisco – Spinels & Opals

2013 GIA Gem Gathering BangkokTanzanite: Facts, Fairytales and Fakes

2013 JCK AGTA Las Vegas – Tanzanite rumors in the industry

2013 Italian Gemmological Conference, Naples – Tanzanite: Facts, Fears & Fairytales

2014 GIA Alumni Assn. San Francisco – Tanzanite: Facts, Fears & Fairytales

2015 AGA Tucson Conference. Collector GemsA Co-Evolution of Life, Minerals, and Technology

2015 GIA Gem Gathering Bangkok

Opal Treatments: Facts, Fears & Fairytales

2016 Mediterranean Gemmological & Jewellery Conference, Valencia, Spain – Phenomenal Prices –Market Value of Phenomenal Gems

2018 NAJA Tucson – Shakiso Ethiopian Emeralds

2018 First Iranian Gemological Symposium, Kish, Iran – Shakiso Ethiopian Emeralds

2019 AGA Tucson Conference – Our Newest Emerald Source (Ethiopia)

2019 AIGS Seminar Hangzhou, China – Rubies, Sapphires, and Emeralds

2019 AGS Arizona Guild Meeting – Hexagons: From Passion to Obsession

2021 IIG – International Institute of Gemology, Bengaluru, IndiaKashmir Trapiche Ruby from the Batakundi mine

6th Mediterranean Gem and Jewellery Conference Thessaloniki, GreeceSpinel history, origins, treatments, marketing & pricing