Saltwater Pearls from the Pre- to Early Columbian Era: A Gemmological and Radiocarbon Dating Study
Examines 85 saltwater natural pearls, reportedly harvested from the Caribbean islands off the coast of Venezuela during the early 16th century, to determine their age.
Cutting Diffraction Gratings to Improve Dispersion (“Fire”) in Diamonds
A new microlithography process developed to create high-resolution diffraction grating patterns on portions of certain facets can improve the dispersion of light and thus the amount of “fire” in a diamond.
A Foundation for Grading the Overall Cut Quality of Round Brilliant Cut Diamonds
The GIA diamond cut grading system described here includes the components of brightness, fire, scintillation, polish and symmetry, as well as weight and durability concerns, into a single overall grade for cut quality for standard round brilliants.
The Wittelsbach Blue
This article describes what is known about the Wittelsbach Blue since it was first reported in 1666, and the gemmological information released to date on this diamond.
Possible “Sister” Stones of the Hope Diamond
A recent study compares a specially created model of the Hope diamond with recent computer models of the French Blue to determine if other stones could have resulted from either recutting.
A Crystallographic Analysis of the Tavernier Blue Diamond
This study uses both historical information and modern data to create a computer model of the Tavernier Blue, orienting the finished diamond within the original diamond crystal.
Celebrating 75 Years of Gems & Gemology
Gems & Gemology, the professional quarterly of GIA, debuted in 1934
Rapid Sight Estimates of Diamond Cutting Quality
A diamond brilliant’s beauty is the result of a complex combination of angles and proportions. In this article, Richard Liddicoat shows gemmologists how to become familiar with how variations in cutting angles can affect a diamond’s face-up appearance.
The Rise to Prominence of the Modern Diamond Cutting Industry in India
this article reviews the rise of the modern diamond cutting industry in India and its impact on the world diamond trade
Curves and Optics in Nontraditional Gemstone Cutting
A series of cuts, designed by the author, exhibit extraordinary optical effects that result from a combination of curved surfaces and plane facets placed to take advantage of internal reflection.