Santa Lucia mine, Puno, Peru
60 km WSW of Juliaca in Puno department.
Light blue to greenish blue or banded massive aragonite
appeared first at the beginning of the 1990s. The colour is due to a small amount of copper, and similar blue copper-bearing aragonite used to be known in old European literature as "zeiringite". It can be cut into cabochons resembling "larimar
", but aragonite is much softer. Aragonite
colour is light blue, density 2.75, hardness 3.5, RI 1.52 - 1.66.
A mixture of azurite
with unidentified black lustrous grains and malachite
is found in the south of the Santa Lucia mine.
Ref: J. Hyrsl, Gemstones of Peru, 2012, p. 36