👉 Gonnardite is a mineral that is not commonly used in modern day mining operations. It was first discovered by French mineralogist Jean-Michel Gonnard in 1923 and is named after him. The mineral is primarily found in the rocks of the Appalachian Mountains, particularly in the vicinity of the Appalachian Trench. Gonnardite is typically encountered as a fine, black or brownish purple to reddish brown crystal with a sharp, smooth surface. It is also