Gems & Gemology

A Solution to Diamond Color Grading Problems

Robert M. Shipley, R.T. Liddicoat

Although GIA’s system for evaluating diamond quality has been an industry benchmark since 1955, it all began with the efforts of Robert Shipley Sr. and Richard T. Liddicoat a decade earlier. This 1941 article troubleshoots the challenges of evaluating diamond color, including the need for controlled light in a standardized, consistent environment. The authors describe a prototype instrument called the Diamolite, which filters and diffuses light for consistent results, and introduce the GIA Colorimeter, a scale for measuring stone color.

You Might Also Like

YMAL AJP
AJP®: New 5-Day Program Offered Worldwide
Learn About NextGem
GIA NextGem™ Diamond Training for Retail
Explore GIA Laboratory Promotional Offers
Explore GIA Laboratory Promotional Offers
Shop the GIA Store
Shop the GIA Store