Provides a comprehensive summary of the special optical effects in gemstones, including opalescence, chatoyancy, asterism, schiller, and iridescence, and investigates the submicron inclusions and nanotextures in each type of phenomenal stone.

Describes the geology, mineralogy, and formation of granitic-composition pegmatites and provides a summary of their worldwide occurrences.

A highly saturated purplish pink to red pezzottaite from a new deposit in Madagascar is encountered in Tucson and tested by GIA researchers.

The Bangkok laboratory studies 35 loose non-nacreous pearls from a wide range of marine mollusk species.