Research Article Search Results

How to Calculate Color from Spectra of Uniaxial Gemstones
Presents a method for accurately predicting the color of a gem material when viewed in any direction as long as the polarized spectra and the viewing angle relative to the c-axis are known.

Micro-Features of Spinel
Provides a visual guide to the internal features of natural, synthetic, and treated spinel, as well as inclusions of spinel in other gemstones.

Internal Structures of Known Pinctada maxima Pearls: Natural Pearls from Wild Marine Mollusks
Presents the internal characteristics of natural P. maxima pearls, obtained from real-time microradiography (RTX) and X-ray computed microtomography (µ-CT) analysis of 774 samples.

Thin-Film Fluid Inclusions in Aquamarine
Oblique fiber-optic illumination of thin-film fluid inclusions in Brazilian aquamarine reveals a kaleidoscopic play of interference colors.

Diamond-Shaped Cloud in Diamond
In a delightful juxtaposition, a diamond-shaped cloud inclusion appears in the center of a 0.53 ct round brilliant diamond.

Remarkably Large Iridescent Healed Fissures Resembling Play-of-Color in Sapphire
Attractive iridescence creates a beautiful “play-of-color” effect on dendritic healed fissures in a blue sapphire.

Opal with Fluid Inclusion and Mobile Bubble
The Carlsbad laboratory recently examined a Mexican opal containing a rare fluid inclusion with a freely moving gas bubble.

Quarterly Crystal: Topaz with Phlogopite
A singly-terminated topaz from Pakistan hosts a prominent phlogopite crystal with strong dichroism and lamellar cleavage planes.

Expanded Diamond Surface Due to Radiation Staining
The author examined a 0.56 ct Fancy grayish bluish green diamond with prominent green radiation stains.

Asterism in Natural Diamond Cabochons
Two cabochons displaying white four-rayed “stars” are fashioned from one large natural diamond crystal.

Unusual Absorption in a Blue Flux-Grown Synthetic Sapphire
The Bangkok lab identified unexpected characteristics in a flux-grown synthetic sapphire.

Baroque-Era Rose Cuts of Colored Stones: Highlights from the Second Half of the Seventeenth Century
Offers a systematic evaluation of rose cuts produced for various colored stones in the latter seventeenth century, based on the examination of rare artifacts that belonged to the archbishops and prince-electors of Trier and Cologne.




