Yanacodo, Yauricocha Parish, Ascencion District, Huancavelica Province, Huancavelica, Peru
Yanacodo in Yauricocha parish, about 30 km W of Huancavelica city.Chalcedony forms veins in a decomposed volcanic rock. It also fills cavities in volcanic rocks.Cavities in the chalcedony are sometimes filled by younger colourless quartz crystals, the youngest phase is yellow calcite, sometimes in rough crystals. The best rough chalcedony yields attractive polished cabochons.
Carnelian is found together with blue chalcedony, where it rarely forms irregular stalactites up to several cm long in volcanic rocks. Good Peruvian agate, 5.7 cm wide with bands of light orange, beige, and red-brown colours. Density 2.61, hardness 7, RI 1.540 - 1.543.
J.Hyrsl (2012) Gemstones of Peru, p. 40