Collinsite is a mineral with formula Ca₂(Mg,Fe²⁺)(PO₄)₂·2H₂O. It was discovered in British Columbia, Canada, and formally described in 1927. It was named in honor of William Henry Collins (1878-1937), director of the Geological Survey of Canada. There are three varieties of the mineral: magnesian collinsite, zincian collinsite, and strontian collinsite. The crystal structure consists of polyhedral chains linked by weak hydrogen bonds.