Martin Steinbach: “An Overview of Asteriated Gems”
20:04
Emmanuel Fritsch: “‘Boehmite Needles’ in Corundum Are Rose Channels”
20:42
Peter Lyckberg: “Gem Pegmatites: An Update on Recent Production”
15:20
Rare Cat's Eye & Star Gems - Emerald, Apatite, Garnet & More!
1:05:05
Playing the Blues: An Overview of Sapphire Treatment | GIA Knowledge Sessions Webinar Series
46:48
Three Precious Gems: Rubies, Emeralds, Sapphires
53:11
Unusual Phenomenal Colored Stones | GIA Knowledge Sessions Webinar Series
22:04
Found Star Sapphires on my New Gemstone Claim!
1:01:37