Read more about diamonds in their diamond education category. All of their diamonds are conflict free.

Recommended by Rothem:

"The Rothem Collection Group are a direct source of GIA certified loose diamonds and formerly sold only to dealers or wholesalers. Since 1942, the Rothem Collection has remained a family owned company specializing in the manufacture of white gold solitaires, Victorian jewelry, antique jewelry and fine jewelry, diamond rings, antique solitaires and Gemstones with special emphasis on diamonds and Jewelry for every wedding party."
(e. g. http://www.rothemcollection.com/ )