This is an extraordinary, large cabinet specimen composed of SOLID ore, with superbly lustrous, silvery blood-red Cinnabar crystals to 7 mm. The crystals shine like mirrors (literally, with that silvery luster), and just a small amount of light causes them to glow gemmy reed. They are that gemmy! The ancient mercury mines at Almaden have been in production since the Roman Age, 2000 years ago. This is a showy, old-time, rich and hefty mercury ore specimen from this historic district. Classic and excellent material. I have not seen a larger specimen for sale which had nice crystals in it.