This is a jewel Rhodochrosite rhomb nestled within Tetrahedrite and needle quartz crystals. The Rhodo is bright and red, sharp and damage-free. The Sweet Home mine in Alma, Colorado produced the best Rhodochrosite crystals in the world (although I absolutley love N'Chwanning Rhodos as well), this miniature was expertly trimmed creating a pleasant curve, and the contrast between black and red is excellent. the mine closed about 8 years ago, and good Rhodos are scarce and very expensive (this piece would typically be $2,500+)