Pasadena Lapidary Society members may well remember that presentation Craig Parrott gave on Oregon Sunstones in 2025. This time he will talk about “Orientation of Phenomena Gemstones”. A phenomena gemstone is a material that shows a special optical effect caused by the way light interacts with its internal structure, inclusions, or crystal growth patterns. The color itself isn’t the main attraction—the visual effect is.
Examples include play of color in opal, asterism in sapphires and rubies, chatoyancy, labradorescence, iridescence, and aventurescence, or schiller in sunstones. In this lecture, we will learn what causes these effects, how to cut, orient, and polish stones to maximize their aesthetics, yield, and value.
This program meeting takes place on Tuesday, July 21, 2026 at 7:00 p.m. in the Fellowship Hall of The Santa Anita Church, 226 W. Colorado Blvd., Arcadia, CA 91007.
Admission is free; open to the public. Enjoy refreshments while checking out the display table; bring a rock specimen you’d like identified. See you there!