Collinsite is a mineral with chemical formula . 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.
{{Infobox mineral | name = Collinsite | category = Phosphate mineral | boxwidth = | image = Collinsite - Rapid Creek.jpg | imagesize = 260px | caption = Crystals of collinsite from the Rapid Creek area of northern Yukon, Canada | formula = | IMAsymbol=Coll | molweight = | strunz = 8.CG.05 | dana = 40.2.2.3 | system = Triclinic | class = Pinacoidal () (same H-M symbol) | symmetry = P | unit cell = a = 5.734(1) Å b = 6.780(1) Å c = 5.441(1) Å α = 97.29°, β = 108.56°, γ = 107.28°; Z = 1 | color = | habit = | twinning = | cleavage = Fair on {001} and {010} | fracture = | tenacity = Brittle | mohs = 3 to 3.5 | luster = Subvitreous, silky if fibrous | polish = | refractive = nα = 1.632nβ = 1.642nγ = 1.657 | opticalprop = Biaxial (+) | birefringence = δ = 0.025 | 2V = 80° (measured) | dispersion = r 2Mg(PO4)2·2H2O, and published in 1974. It consists of chains of corner-sharing (MgΦ6) octahedra and (PO4) tetrahedra. Four of the Mg ligands link to (PO4) groups and the other two to water molecules. Two of the ligands in the (PO4) group link to (MgΦ6) octahedra and the other two link to calcium atoms and act as hydrogen bond acceptors. Weak hydrogen bonds link chains together and force separation between them. The separation gives room for interstitial, eight-coordinated calcium between chains.
==History== thumb|300px|Diagram of the phosphorite nodules from François Lake; collinsite is the lightly colored layer Collinsite was discovered prior to 1927 near François Lake, British Columbia. In a , phosphorite nodules were discovered that consisted of a fragment of andesite enclosed by concentric layers of phosphate minerals coated in wurtzilite. The phosphate layers were composed of a mineral named quercyite (since determined to be improperly classified) and the new mineral collinsite. The François Lake collinsite was light-brown and consisted of sub-centimeter blades.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).