Robert R. Coenraads and Claudio Canut de Bon, March 1, 2000
Lapis lazuli has been mined from the Coquimbo Region of Chile since 1905.
Read MoreGary W. Bowersox, December 1, 1985
An overview of the plentiful and various gem materials being discovered and produced in Afghanistan.
Read MoreGeorge Bosshart, December 1, 1983
The properties of a novel gemmological imitation, cobalt glass.
Read MoreJean Wyart, Pierre Bariand, December 1, 1981
lapis-lazuli is an ornamental stone (figure 1) that has been found in the artefacts of some of the oldest known civilisations.
Read More