I recently discovered this website as I was going through  a pile up of old Lapidary Journals. This particular web site was written up in their April 2013 issue. Ok, so I am a little late, but in case some of you are not familiar with this site, I suggest you log on. GEMDAT.ORG is dedicated to gemological information, photos, and gem localities and was launched by Jolyon Ralph, the founder of mind.org mineral information website, with his wife, Katya.

GEMDAT.ORG had its official launch in 2013 and at that time contained information on over 500 different gemstones, gem varieties, and lapidary materials, along with worldwide gem locality maps information on synthetics, treatments and inclusions, and over 4,500 gem photos covering a broad spectrum of gemstones, colors, shapes and sizes. 

thanks a lot