Nice to meet you, Djalma

Djalma Guimarães was born in  Santa Luzia, Minas Gerais, on November 5th, 1894. He was one of the main Brazilian geologists responsible for important discoveries.

In 1913, he enrolled at Escola de Minas de Ouro Preto, one of the main geoscience learning centers in Brazil, founded by Henry Gorceix, in 1876, as mission requested by D. Pedro II.

Soon after his graduation, in 1919, he started his career in Rio de Janeiro working with hill destruction to build roads. In 2021, he entered to the previous Geological and Mineralogical Service of Brazil.

The microscopy was his main work tool, it helped him with important findings, including the discovery in Araxá, Minas Gerais, of one of the biggest Niobium deposits on earth. 

The geologist Djalma Guimarães using his microscopy, his main working tool.

Among his findings using the microscopy, there are the identification and description of four new minerals: Arrojadite, Eschwegite, Pennaite and Giannetite. The rock thin section shown in this picture contains Giannetite.

In 1938, his scientific researches reached international importance,  when he published a paper about the formation process of igneous rocks in a German journal. He became one of the most important researchers in this field.

In the 1940’s, when he was already an experienced office geologist, Djalma performed analysis in apatite samples from Araxá, Minas Gerais, and requested some borehole research in the region.

This research led to a strategic finding: a great phosphate deposit, minerals used in fertilizer applied in agriculture. The product offer raising contributed to the reduction of production costs. 

At that time, the apatite research data and an high tech aerial survey, 
indicated the presence of Niobium as well. The lab analysis confirmed the high concentration of this metal.

The math used to establish the deposit dimensions reached a great internacional repercussion, because it presented one of the biggest Niobium reserves in the world, with over 185 tons, in Araxá, Minas Gerais.

During many opportunities in which he was invited to give a speech, he used to show his passion about his work, especially when it was 
addressed to students or graduates. 

In one of his lectures, he discussed the political, economical and cultural dimensions of scientific work, showing his worries about the intensification of Military Dictatorship in Brazil, after 1964.

The Guimarãesita was named in honor of Djalma Guimarães. Chemical composition: Ca2Be4Zn5(PO4)6(OH)4·6H2O

This mineral was originally named Djalmaita by João Pandiá Calógeras. Later it was renamed as uranomicrolita.