Named after Serendib, the old Arabic name for Sri Lanka, this is a very rare and HUGE crystal of the species. I could not believe it when I saw it, having thought a 1-cm crystal seen in the past was huge, already. This species is a very rare, seldom crystallized member of the sapphirine family of minerals. Because large CRYSTALLIZED examples of this extremely rare species were so important, confirmatory analysis was done by Dr. George Rossman at Caltech on these, when the first samples trickled out around the early 2000's with gem dealer Bill Larson. Likewise, I had a lucky find when I spotted this extremely ugly and dark crystal lurking in with beautiful spinel and ruby stones, at a gem dealer's booth in Tucson of 2011. It is about 25 carats, mass. It is well terminated. Interestingly, some crystals have been sold as gem rough (they are faintly translucent when cut) for the collectors of rare gemstones. Joe Budd Photos