This is a large (25cm x 15cm x 15 xm) coralloid formation of Aragonite from Santa Eulalia, Chihuahua, Mexico. I don't know if coralloid is an official term, but this specimen looks enough like coral that many people assume it is coral. At the extremities it is covered by tiny crystals. The whole specimen glows an intense green and lit up brightly even in a well lit room. The dealer I bought it from had no idea that it fluoresced. There is calcite on the piece as well, but it is hard to discern. I believe the calcite fluoresces a pale blue, but it is very hard to see as the green dominates. The specimen glows bright green under shortwave. The photos were taken with a Nikon D80 camera with a Nikon 28-80mm Zoom Macro lens set to 28mm. The camera settings for the short wave photo were ISO 100, 20 seconds at f/22 and the specimen was lit using a handheld SuperBright II. The white light picture was taken using a flash. I do not have a long wave picture, but using a 365nm light it glows a far less intense green at the ends of the stalks, but more of a bright white or orange in the interior as well as blue here and there.