Life and work
Born into a family of doctors and pharmacists is interested Lacroix, inspired by the writings of René -Just Haiiy, Pisani and Ours -Pierre -Armand Petit- Dufrenoy, already in the Lyceum of Mineralogy. At the age of 18 he was a member of the Mineralogical Society of France (société de minéralogie de France) accepted. After a study pharmacy in the years 1881 to 1883, he continued his mineralogical studies away again and entered simultaneously into the Pharmaceutical School of Paris. He was able to enter into the service of Alfred Des Cloizeauxs, making him stood his laboratories. Then he rose to Assistant Professor Ferdinand Fouqué on petrology at the Collège de France, where he met microscopic methods and devices of the mineralogy. Lacroix was only allowed to complete his dissertation in Fouqué, when he agreed to marry his daughter.
He took courses at Charles Friedel at the Sorbonne, at the recently already the later pharmacist and volcanologist Albert Brun had studied, and François Ernest Mallard (1833-1894) at the École des Mines. In the summer of 1884 he traveled to Norway and Sweden, in 1887 was followed by a trip through northern Italy, Sardinia and Elba. Further studies he conducted in the Pyrenees. He supplemented the collection of the National Museum of Natural History at the Collège de France. He was at this time also a 1- degree in pharmacy.
His scientific doctoral degree he earned in 1889 with a thesis on the results of his travels and evaluations of the preparations at the Collège de France and other trips to Canada, Italy and Germany. College with the Natural History Museum as one of the leading research institutes of Mineralogy was his constant travels. One of his most important works is Mineralogy de la France et de ses Colonies (1893-1898), other important works were produced in collaboration with Auguste Michel - Lévy ( 1844-1911 ).
Lacroix became interested especially for volcanism and metamorphism and traveled to Santorini, Madagascar and 1902 to Martinique to observe the eruption of Mont Pelé. There he met with other volcanologists time as Thomas Jaggar, Jr. and Frank Perret. Lacroix was instrumental in the founding of the world's second volcano observatory.
In 1904 he became a member of the Académie des Sciences, whose permanent secretary he was in 1914 and remained for 34 years. In 1906 he observed an eruption of Vesuvius and Etna in 1908. His regular trips he set in 1924 in Italy and 1926 in Spain continues. At the Pan - Pacific Congress in Tokyo in 1926, he participated as the representative of France. In 1936 he withdrew from the daily operations of the research something back, continued his investigations, however, after the death of his wife in 1944 in its entirety until his death in 1948 continued.
Lacroix is regarded as the first to describe the minerals Gonnardite (1896 ), Villiaumit (1908), Soumansit or Sousmansite (1910, identical to Wardit ) Betafit (1912 ) and Serandit ( 1931).
A newly discovered and described in 1914 by František Slavik mineral received his honor the name Lacroixit.
The Geological Society of London awarded him in 1917 with the Wollaston Medal. In 1930 he received the Penrose Medal.