Feature Gems & Gemology, Spring 2000, Volume 36, No. 1

Lapis Lazuli from the Coquimbo Region, Chile

Lapis lazuli has been mined from the Coquimbo Region of Chile since 1905. Some of this material approaches the quality of fine lapis lazuli from Afghanistan. The Chilean material is composed of blue lazurite, together with wollastonite, calcite, haüyne, diopside, pyrite, and minor quantities of other minerals. The deposit is located in the Andes Mountains at an elevation of 3,500 m; it is hosted by a contact-metamorphosed limestone that was later metasomatized to introduce sulfur, a necessary component for the formation of lazurite. Two companies are currently mining the deposit, Las Flores de Los Andes S.A. and Compañía Minera LapisChile S.A., and today they produce about 150 tonnes of material annually. Much of the lapis lazuli is processed locally, for use in fine jewelry, ornamental objects, and building materials such as tabletops or tiles.