Lattice-Diffused Sapphire • Titanium Diffusion • Rumble in the Jungle
Surface ('bulk') diffusion-treated corundums (SDTCs) created a stir in the Bangkok market in 1990. This article looks at the original patents and cont...
Brilliance, Windows & Extinction in Gems
A discussion of brilliance, windows and extinction as they relate to the face-up appearance of colored gemstones. Diagrams demonstrate that extinction...
Dismantling Diamond Grading • The Naked Eye • A Diamond's Worst Friend
Probably the first opinion piece I ever wrote, it was my take on diamond grading from the standpoint of someone working with colored stones.