Dislocation Chain in Oregon Sunstone
The author recently examined a high-quality faceted orangy red Oregon sunstone weighing 6.77 ct. Examined under magnification with fiber-optic illumination, the stone displayed an unusual inclusion that consisted of a decorated dislocation string (see above). Copper exsolution platelets, which are common in Oregon sunstone, were also observed. In this example, the decorated dislocation followed a rectangular pattern, consistent with the crystal structure of the host feldspar. This unique light-scattering dislocation chain is the first that the author has encountered in Oregon sunstone.