Dolomieu, Déodat Guy Silvain Tancrède Gratet de

Dolomieu, Déodat Guy Silvain Tancrède Gratet de (dāôdä` gē sēlvăN` täNkrĕd` grätā` də dôlômyö`), 1750–1801, French geologist. He contributed to the study of volcanic geology, especially through examination and comparison of the products of volcanoes. In 1791 he reported on the character of the mineral dolomite, named for him. He wrote several works on his findings during geological journeys, specially in S Europe, and is known for his Sur la philosophie mineralogique (1801).