Home > Laskowski Ⅸ – October 7 > MS1983 Guanacoite


Guanacoite is a hydrous copper magnesium arsenate, and a member of akrochordite group. Witzke et al. (2006) named the species after the Guanaco mine, its type locality. Kyono (2008) demonstrated significant compositional variation in guanacoite from Chile, and suggests that a separate species richer in magnesium also exists. This separate species remains unnamed.

Guanacoite forms bright blue crystals in aggregate 4 mm across, with dolomite rhombohedra. The matrix consists of altered sulfide, quartz, and chrysocolla. This specimen is from the type locality; perhaps it also contains Kyono's new mineral. From the collection of E.R. Laskowski (1949-2020), a mining engineer who retired to Tucson, Arizona.

Price: $75

Item code: MS1983

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