Lecontite | |
---|---|
General | |
Category | Sulfate mineral |
Formula (repeating unit) | (NH4,K)NaSO4·2H2O |
IMA symbol | Lcn [1] |
Strunz classification | 7.CD.15 |
Crystal system | Orthorhombic |
Identification | |
Color | Colorless |
Cleavage | {011} Distinct [2] |
Mohs scale hardness | 2–2.5 |
Luster | Vitreous to dull |
Streak | White |
Diaphaneity | Transparent to translucent |
Specific gravity | 1.745 g/cc [3] |
Density | 1.745 g/cc |
Refractive index | nα = 1.440 nβ = 1.454 nγ = 1.455 [3] |
Birefringence | δ = 0.015 [3] |
Lecontite ( sodium ammonium sulfate dihydrate, with potassium substituting for some ammonium, typically about a fourth [2]) is a sulfate mineral with the formula (NH4,K)NaSO4·2H2O. It was found by John Lawrence LeConte in Las Piedras Cave in Honduras as a breakdown product of bat guano, including crystals up to an inch long [3] and identified as a separate mineral by W.J. Taylor in 1858. [4] As of 1963 most natural specimens came from the same cave. [5]
Lecontite can easily be synthesized by reacting ammonium sulfate with sodium sulfate in aqueous solution and crystallized. [6]
Lecontite | |
---|---|
General | |
Category | Sulfate mineral |
Formula (repeating unit) | (NH4,K)NaSO4·2H2O |
IMA symbol | Lcn [1] |
Strunz classification | 7.CD.15 |
Crystal system | Orthorhombic |
Identification | |
Color | Colorless |
Cleavage | {011} Distinct [2] |
Mohs scale hardness | 2–2.5 |
Luster | Vitreous to dull |
Streak | White |
Diaphaneity | Transparent to translucent |
Specific gravity | 1.745 g/cc [3] |
Density | 1.745 g/cc |
Refractive index | nα = 1.440 nβ = 1.454 nγ = 1.455 [3] |
Birefringence | δ = 0.015 [3] |
Lecontite ( sodium ammonium sulfate dihydrate, with potassium substituting for some ammonium, typically about a fourth [2]) is a sulfate mineral with the formula (NH4,K)NaSO4·2H2O. It was found by John Lawrence LeConte in Las Piedras Cave in Honduras as a breakdown product of bat guano, including crystals up to an inch long [3] and identified as a separate mineral by W.J. Taylor in 1858. [4] As of 1963 most natural specimens came from the same cave. [5]
Lecontite can easily be synthesized by reacting ammonium sulfate with sodium sulfate in aqueous solution and crystallized. [6]