Seamanite
From Wikipedia, the free encyclopedia
Seamanite, named for discoverer Arthur E. Seaman, is a rare manganese boron phosphate mineral with formula Mn3[B(OH)4](PO4)(OH)2. The yellow to pink mineral occurs as small, needle-shaped crystals. It was first discovered in 1917 from a mine in Iron County, Michigan, United States and identified in 1930. As of 2012[update], seamanite is known from four sites in Michigan and South Australia.
Quick Facts General, Category ...
Seamanite | |
---|---|
General | |
Category | Borate minerals |
Formula (repeating unit) | Mn3[B(OH)4](PO4)(OH)2[1] |
IMA symbol | Sem[2] |
Strunz classification | 6.AC.65[3] |
Dana classification | 43.4.5.1[1] |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)[4] |
Space group | Pbnm |
Unit cell | a = 7.811 Å, b = 15.114 Å c = 6.691 Å, Z = 4 |
Identification | |
Formula mass | 372.64 g/mol[3] |
Color | yellow, yellow-brown, pink[1] |
Crystal habit | acicular[3] |
Cleavage | distinct on {001}[4] |
Fracture | brittle[3] |
Tenacity | brittle[4] |
Mohs scale hardness | 4[1] |
Luster | vitreous[3] |
Streak | white[3] |
Diaphaneity | transparent[4] |
Specific gravity | 3.08[1] |
Density | 3.08–3.128 g/cm3[4] |
Refractive index | nα = 1.640, nβ = 1.663, nγ = 1.665[5] |
Birefringence | δ = 0.025[1] |
2V angle | ≈40°[5] |
Dispersion | weak[1] |
Ultraviolet fluorescence | none[3] |
Solubility | in cold, dilute acids[1] |
References | [4] |
Close