"Exploring Gem pegmatites", a Field Gemology Talk webinar with Peter Lyckberg
2:10:14
"Let's Read & Talk about Gemology" with John L. Emmett
3:14:33
"People & Places: Journey in Humanitarian Gemology", a webinar with Richard W. Hughes
2:19:52
"Let's Read & Talk about Gemology" with Antoinette L. Matlins
2:42:18
«Geology of Gems: 30+ years of a fascinating Scientific & Human Adventure », with Gaston Giuliani
2:59:56
Let's read & talk about Gemology with Edward Boehm.
2:06:08
"Let's Read & Talk about Gemology" with John I. Koivula
2:45:07
Lets read and talk about gemology with John Saul, author of "A Geologist Speculates"
2:26:38