Prehnite (Rondelle)(Faceted)(6x4mm)(15.5"Strand)Sold By Strand Prehnite is a silicate mineral made up of calcium and aluminum. It comes in various colors; white, blue, pink, orange, but most often Green. Green prehnite may also come with inclusions made of Epidote such as the beads seen here. These particular beads have been cut and polished into faceted rondelle beads. Origin: Africa Metaphysical Properties: Promotes Harmony and Protection Mohs Hardness: 6 6. 5 Average Strand Length: 15. 5in Beads