A classic, old-time and rare pseudomorph and combination specimen from the Corkscrew Mine of Death Valley, California. This superb, two-sided specimen consists of colemanite after sharp, blocky, parallel-growth, inyoite crystals. The fine pseudomorphs, front and back, are completely covered with two colors of brown and tan, sparkly todorokite microcrystals. Todorokite is a very complex manganese hydroxide. This is older material from the 1960s-70s and comes from the Jamie Bird Collection, a California collector from the 1960s-1980s. The blue ink on the accompanying label is characteristic of the 1960s.