A brightly fluorescent and phosphorescent calcite cleavage rhomb from Challenger Cave, Nuevo Leon, Mexico. This specimen shows classic Terlingua-type fluorescence under UV- a blue response with bright and lasting phosphorescence under short wave, and a bright pink response with brief, dim phosphorescence under long wave. This calcite also fluoresces bright yellow/white with phosphorescence under mid wave UV. These specimens from Nuevo Leon, Mexico, are fairly common and look like ice cubes under visible light, but show an almost magical fluorescent response under all UV wavelengths.
46.3 x 34.5 x 19.2 mm, and weighs 58 grams.
Challenger cave is a series of 7 caverns that has historically been a prolific source for these optically clear and brightly fluorescent calcite cleavage rhombs.