Nacrite

General Information: Chemical Formula:Al2Si2O5(OH)4 Composition:(Molecular Weight = 258.16 gm)Aluminum 20.90 % AlSilicon 21.76 % SiHydrogen 1.56 % H Oxygen 55.78 % O  Empirical Formula: Al2Si2O5(OH)4 Name Origin:From the French, nacre, "mother-of-pearl."Physical Properties: Cleavage:[001] Perfect Color:colorless, white, yellowish, or brownish. Density:2.6 Diaphaniety:Transparent Habits:Massive - Uniformly indistinguishable crystals forming large masses., Scaly - Morphology like fish scales., Earthy - Dull, clay-like texture with no visible crystalline affinities, (e .g. howlite). Hardness:1 - Talc Luster:Pearly Streak:whiteMore details...