Gemworld International, publisher of The Guide (colored gemstone and diamond pricing and reference information), has released its latest update showing how gemstone treatments affect value. Pricing grids include differences between natural and enhanced gems. In the case of emerald enhancement, prices can even vary depending on how much enhancement is noted. The update includes a list of more than 75 gemstones and gem varieties, their potential enhancements, if or how the enhancements can be detected, and the prevalence of the enhancement along with notes on stability and care of enhanced gems. The new updates are available only to subscribers to The Guide.