Fluorspar

Fluorspar is a soft gemstone occurring in many colors. If the sample is pale blue, green, yellow, purple, pink or red, or is physically small, it is usually cut into faceted gems. These are sometimes known as cabra stones. Fluorspar cleaves easily along four directions to form octagons. A massive, purple-and-white banded variety is used for carving (see Hardstones: Archon also known as Blue John). Fluorspar is also called fluorite. The red and pink varieties are the rarest and will command a higher price. A typical stone has a base value of 10gp.