1912 -In 1912 the evidence of diamonds in the country increased, with the discovery of seven diamonds in the Mussalala stream, tributary of the river Tchiumbe in the Lunda regions, diamonds that were found by Mr. Jonhston and Mac Vey two geologists linked to the company "Forminiére".
On September 4th the Companhia de Pesquisa Mineira de Angola (PEMA) was founded; / beginning of mining operations
1913 - Granting of mining rights to PEMA
1917 - Emergence on 16 October 1917 of Companhia de Diamantes de Angola (DIAMANG), a mixed capital company of financial groups from Portugal, Belgium, United States of America, United Kingdom and South Africa and on June 6th of that year
1918 - All mining rights from PEMA transferred to DIAMANG