The author recently examined a 3.46 ct bluish violet to purple color-change sapphire measuring 9.04 × 7.61 × 5.47 mm. Microscopic examination revealed a scene reminiscent of shooting stars in a night sky, created by numerous Rose channels against a backdrop of scattered zircon crystals (see above). Commonly occurring in various gems including calcite, diamond, and sapphire, Rose channels are created by intersecting twin lamellae, formed by twinning along the rhombohedral faces (F. Notari et al., “‘Boehmite needles’ in corundum are Rose channels,” Fall 2018 G&G, p. 257).
Michaela Damba is a senior staff gemologist at GIA in Carlsbad, California.
The author recently examined a 3.46 ct bluish violet to purple color-change sapphire measuring 9.04 × 7.61 × 5.47 mm. Microscopic examination revealed a scene reminiscent of shooting stars in a night sky, created by numerous Rose channels against a backdrop of scattered zircon crystals (see above). Commonly occurring in various gems including calcite, diamond, and sapphire, Rose channels are created by intersecting twin lamellae, formed by twinning along the rhombohedral faces (F. Notari et al., “‘Boehmite needles’ in corundum are Rose channels,” Fall 2018 G&G, p. 257).
Michaela Damba is a senior staff gemologist at GIA in Carlsbad, California.
