This rare large tourmaline, which shows here as very dark but actually is a dark deep blue indicolite with strong lighting, is thought to be the largest tourmaline crystal found in the modern mining era at the Oceanview Mine. It is noted as such and illustrated in the Rocks & Minerals article on the mine from around 2010, and was sold by the mine owner Jeffrey Swanger to collector Brent Lockhart, from where it went into the George Elling collection for many years. A significant San Diego County tourmaline, for the location and size!