In the Americas, the Incas, Molles, Diaguitas and other pre-Columbian cultures have, for over 2000 years, used lapis lazuli to ornament masks and other artifacts. This was done by extracting the stone from the same deposit located at 3600 meters above-sea-level in the Andes Mountains in the area of Ovalle, Chile, and which today is named Las Flores de los Andes S. A.
In 1851, the location of this deposit was mapped, and in 1894 Las Flores de Los Andes was officially registered as a mining property of Chile.
In 1950, its commercial mining was begun, and in 1989, the company Las Flores de Los Andes S. a. built a 60 km. access road, that allowed for the transport of machinery to the mine in order to start the extraction of material in larger quantities and sizes. Because of the extreme conditions this site can only be mined during the summer months.
The Flor de los Andes lapis lazuli deposit is located at an elevation of 3,600mtr in the high cordillera of Ovalle, in the Limarí province of Chile, only 200 mt from the border with Argentina, in the outer zone of a contact metamorphic aureole.
The aureole. can be divided into three mineralogical zones: I) wollastonite marbles, II) andradite-grossular skarns; and III) hedenbergite hornfels. The physical conditions for the metamorphism are estimated in the range of 500 and 550°C, and at 1.5 kb total pressure.
The lapis lazuli deposit is composed of lazurite, which gives it the characteristic blue colour, with small quantities of hauyne, wollastonite, diopside, scapolite, calcite and traces of afghanite, tremolite, allanite, pyrite, pyrrhotite, arsenopyrite and chalcopyrite.
The Chilean deposit is related to Mesozoic limestone intruded by a Tertiary monzogranitic pluton and it formed in two stages:
a) contact metamorphism (24 Ma) during which the calcsilicates and hauyne, with high concentrations of sodium and aluminum, formed in the limestone, and
b) hydrothermal alteration (13-9 Ma) during which sulfur was added, forming lazurite and thus, lapis lazuli.