Gemworld International Inc. has released the Spring & Summer issue of The Guide to Colored Stones, considered the industry standard for colored stone pricing. Pricing updates include Tahitian pearls, emeralds, and sapphires and rubies, which have seen changes in demand.

The Color Book is available as part of a subscription to The Guide. A year’s subscription includes Diamonds bimonthly, Color biannually, the Gem Market News bimonthly, and a reference manual.

Gemworld International Inc., Northbrook, Ill.; (847) 564-0555, www.gemguide.com.