Dumortierite is a rare blue or violet mineral occurring typically as needles and fibrous masses in gneiss and schist. It consists of an aluminum and iron borosilicate. Dumortierite occurs in white, brown, black, red and reddish brown varieties, but most often is a beautiful violet, violet-blue or deep blue color.
Deep blue dumortierite is referred to as the “blue denim stone.” It is named for a French paleontologist, Eugène Dumortier, who discovered it in 1881 in the Rhône-Alps region of France. Dumortierite is used to manufacture high grade porcelain and spark plugs, among other things.
Dumortierite is believed to be a stone of self-reliance and discipline. It is said to promote patience and orderliness. The stone is credited for promoting insight and aiding memory.