Persian  Turquoise Over the past decades, the Geological Survey of Iran (GSI) has conducted many field investigations revealing numerous gemstone occurrences in the Khorasan Razavi Province (KRP) in Northeast Iran. Agate, onyx, amethyst, jasper, opal, rock crystal (clear quartz), rose quartz, orthoclase, tourmaline, fluorite, epidote, garnet group, ilmenite, aragonite, chrysocolla, and Persian Turquoise are some […]