armstrongite

{{Infobox mineral | name = Armstrongite | image = Armstrongite.jpg | alt = | caption = Armstrongite found in Mongolia | category = Phyllosilicate minerals | formula = CaZr[Si6O15]·3H2O |IMAsymbol=Asg | strunz = 9.EA.35 | dana = | system = Monoclinic | class = | symmetry = | unit cell = | color = Dark to light brown | habit = | twinning = | cleavage = Perfect on {001}, good on {100} | fracture = | tenacity = Very brittle | mohs = 4.5 | luster = Vitreous | streak = Brownish white | diaphaneity = Translucent | gravity = | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = }}

Armstrongite (CaZr[Si6O15]·3H2O) is a silicate mineral.