I recently gave a two hour lecture on "ANCIENT JEWELRY - A VISUAL JOURNEY of ADORNMENT" sponsored by RENESAN - Institute for Lifelong Learning in Santa Fe, New Mexico.  I have several other powerpoint presentations available for groups on "The Lure and Lore of Gemstones" as well as "Gemstone ID: What you should know when buying jewelry".  Contact:  info@bhwydesigns.com