"Let's Read & Talk about Gemology" with John L. Emmett
1:44:16
Let's read & talk about Gemology with Richard W. Hughes, author of "Ruby & Sapphire"
2:19:52
"Let's Read & Talk about Gemology" with Antoinette L. Matlins
2:26:38
«30 years in Bangkok from Treatments to Gem Cutting & Trading», with Karim Guerchouche
2:59:56
Let's read & talk about Gemology with Edward Boehm.
2:42:18
«Geology of Gems: 30+ years of a fascinating Scientific & Human Adventure », with Gaston Giuliani
1:41:49
Einstein: Ben Spinoza'nın Tanrısına İnanıyorum, Spinoza Felsefesinin Temel Öğretileri | Tamamı
2:45:07
Lets read and talk about gemology with John Saul, author of "A Geologist Speculates"
2:06:08