samuelsonite

{{Infobox mineral | name = Samuelsonite | category = Phosphate minerals | boxwidth = | boxbgcolor = | image = Samuelsonite.png | imagesize = | caption = | formula = (Ca,Ba)Ca8Fe22+Mn22+Al2[(OH)2(PO4)10] | IMAsymbol = Sms | molweight = | strunz = 8.BF.10 | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = C2/m | unit cell = a= 18.495 Å, b= 6.805 Å c= 14.000 Å, β= 112.75°; Z = 2 | color = Pale yellow | habit = Prismatic crystals, elongated and striated | cleavage = Fair on {001} | fracture = | tenacity = | mohs = 5 | luster = Adamantine, Sub-Adamantine | refractive = nα = 1.645 - 1.648 nβ = 1.650 - 1.655 nγ = 1.655 - 1.667 | opticalprop = Biaxial (+) | birefringence = 0.0100-0.0190 | pleochroism = | streak = White | gravity = 3.353 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent | other = | references = }}

Samuelsonite is a complex mineral that is found near North Groton, Grafton County, New Hampshire, US. Additionally, it is most commonly found as a secondary mineral in granite pegmatite. Samuelsonite is named after Peter B. Samuelson, a prospector from Rumney, New Hampshire.