franklinphilite

{{infobox mineral | name = Franklinphilite | image = | alt = | caption = | category = Phyllosilicate minerals | group = Stilpnomelane group | formula = (with n~6) | IMAsymbol = Fkp | strunz = 9.EG.40 | dana = | system = Triclinic Unknown space group | unit cell = a = 5.52, b = 9.56 c = 36.57 [Å]; Z = 6 α = β = γ = essentially 90° | molweight = | color = Dark brown | colour = | habit = Fine radial aggregates; pseudo-hexagonal | twinning = | cleavage = Imperfect on {001} | fracture = | tenacity = Brittle | mohs = 4 | luster = Vitreous to slightly resinous | streak = | diaphaneity = Translucent to nearly opaque | gravity = 2.6 - 2.8 | density = | polish = | opticalprop = Biaxial (-) | refractive = nα = 1.545 nβ = 1.583 nγ = 1.583 | birefringence = δ = 0.038 | pleochroism = Distinct; X = pale yellow; Y = Z = deep brown | 2V = 10° | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | references = }} Franklinphilite is a phyllosilicate of the stilpnomelane group. Known from only two localities (with a third unconfirmed locality in Switzerland) It was found exclusively from the Franklin and Sterling Hill mines in Franklin, Sussex County, New Jersey. until 2013, when a locality in Wales was confirmed

== Composition ==