Gemworld International has released the newest edition of the Reference Manual, the companion to The Guide. With more than 200 pages, the manual serves as a field guide, working gemological reference, and training tool, among other uses. Sections in the manual include: Appraisal, Diamonds, Grading Color, Color Systems, Treatments, Origin, Pearls, Opals, Jade, Reference Data, and Photo Gallery.

For more information, contact Gemworld International at (847) 564-0555, www.gemguide.com.