Nickelblödite

Nickelblödite is a rare nickel sulfate mineral with the formula Na₂Ni(SO₄)₂·4H₂O.[1][3] Nickelblödite was discovered in nickel mines in Carr Boyd Rocks and Kambalda, Western Australia.[1] The mineral is a nickel-analogue of blödite, changoite, cobaltoblödite and manganoblödite - other representatives of the blödite group.[3]

Nickelblödite
A crust of greenish nickelblödite on gossan; obtained from dealer at the Minerant (mineral show of the MKA) 2016
General
Category	Sulfate mineral
Formula (repeating unit)	Na2Ni(SO4)2·4H2O
Strunz classification	7.CC.50
Dana classification	29.3.3.2
Crystal system	Monoclinic
Crystal class	Prismatic (2/m) (same H-M symbol)
Space group	P21/a
Unit cell	a = 10.87, b = 8.07 c = 5.46 [Å]; β = 100.43°; Z = 2
Identification
Color	Pale yellowish-green to pale green
Crystal habit	Flat crystallites
Diaphaneity	Translucent
Specific gravity	2.43 (calculated)
Optical properties	Biaxal (-)
Refractive index	nα=1.50-1.51, nβ=1.51-1.52, nγ=1.51-1.52 (approximated)
Common impurities	Mg, Fe
References	[1][2][3]

Nickelblödite contains small admixtures of magnesium and iron.[2]

Minerals associating with nickelblödite include violarite, morenosite, halite, pyrite, and siderite.[2]

References

1. Nickel, E.W., and Bridge, P.J., 1977. Nickelblödite, Na₂Ni(SO₄)₂·4H₂O, a new mineral from Western Australia. Mineralogical Magazine 41, 37-41
2. "Nickelblödite - Handbook of Mineralogy" (PDF). Handbookofmineralogy.org. Retrieved 2016-03-11.
3. "Nickelblödite: Nickelblödite mineral information and data". Mindat.org. Retrieved 2016-03-11.