Natural Blue Apatite Smooth Heart Drops Briolette Strand Length 9 Inches and Size 5mm to 8mm approx. Apatite is one of a few minerals produced and used by biological micro-environmental systems. Apatite is the defining mineral for 5 on the Mohs scale. Hydroxyapatite, also known as hydroxylapatite, is the major component of tooth enamel and bone mineral.