aragonite

azurite (?); dolomite (?); malachite

Tight, slightly radiating sprays of sub-parallel, prismatic aragonite crystals (to 20 mm) traversing a vug in partly oxidised sulphide. The aragonite is essentially colourless-white but with very subtle, localised, pale green and orange blushes. The hosting vug is lined with colourless, curvilinear rhombs of dolomite (?). Traces of malachite and azurite (?) are visible on the oxidising sulphide.

Semi-quantitative EDS indicates that the aragonite is essentially pure CaCO3 with no significant content of Pb or Zn (Frank Keutsch; Harvard University, 2025).

The specimen was formerly in the Bill Pinch Collection, but with no record of provenance or location in the mine other than a comment on the Pinch label that this is an “old specimen.”