Fluor spar, also known as fluorite, is a mineral that is commonly found in various countries around the world. This mineral is typically used in the manufacturing of steel, aluminum, and cement, among other industrial processes. However, there are several synonyms for fluor spar that are frequently used in different parts of the world. These include Derbyshire Blue John, Illinois fluorite, and Lavender fluorite. Other popular synonyms for fluor spar include Blue John, fluorspar, and Blue Billy. These synonyms may be often used interchangeably in conversation, but they all refer to the same valuable mineral that plays a significant role in global industrial production.