Category: gems gemology

Figure 1. The concept of the rock cycle demonstrates the interplay between sedimentary, metamorphic, and igneous rocks. Photos by Robert Weldon (courtesy of Cody Opal), Orasa Weldon, and John I. Koivula, respectively. Over the eons, the interminable shifting of Earth’s landmasses has dramatically altered ...

Figure 1. This 34.59 ct CVD-grown diamond (24.94 × 13.95 × 9.39 mm), produced by Ethereal Green Diamond in India, is the largest GIA has tested. Photo by Johnny (Chak Wan) Leung. Chemical vapor deposition (CVD) growth technology has advanced significantly over the last ...