This large matrix specimen is apparently an ore rich in colbaltite/cobalt, and it hosts atop a niec 6-cm-tall display face of beautiful, metallic, acicular erythrite crystals. I am tempted to trim this patch off the big rock, but the overall piece shows so much about the environment, and preserves vein formations, it is too interesting to break up. They sparkle in any light. According to MINDAT: La Blanco is a small Co-Cu deposit close to the town of Freirina; mined on a small scale in the 19th century (Ref.: Maurizio Dini). It is the most likely source for this specimen because a Xerox of the original museum label (with specimen PAS-182a) gives "San Juan, Chili" as the locality, and because that label also states the presence of "Asbolite." Asbolite is a now-discredited name for a "cobaltian wad" of interlocking acicular erythrite crystals. According to MINDAT, this is the only documented old locality which produced both erythrite and "asbolite."