Celestite, or Celestine, is the principal source of the element strontium. It gained its name from its occasional sky blue "celestial" color but can also be colorless and yellow. It will sometimes be found with tints or red, green and brown. Celestine typically can be found in sedimentary rocks, and will often be associated with other minerals such as gypsum and halite.
Celestine can typically be found worldwide in small quantities but our pale blue crystal specimens were found in Madagascar.