Niedermayrite

{{short description|Sulfate mineral}}

{{Infobox mineral

| name = Niedermayrite

| image = Niedermayrite-382305.jpg

| alt =

| caption =

| category = Sulfate mineral

| formula = Cu₄Cd(SO₄)₂(OH)₆·4H₂O

| IMAsymbol = Ndm{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3 |pages=291–320|doi=10.1180/mgm.2021.43 |bibcode=2021MinM...85..291W |s2cid=235729616 |doi-access=free}}

| molweight =

| strunz = 7.DD.30

| system = Monoclinic

| class = Prismatic (2/m)
(same H-M symbol)

| symmetry = P2₁/m

| unit cell = a = 5.543(1), b = 21.995(4)
c = 6.079(1) [Å]; β = 92.04(3)°; Z = 2

| color = Bluish green

| colour =

| habit = Platy euhedral crystals and as green crusts

| twinning =

| cleavage = Perfect on {010}

| fracture =

| tenacity = Brittle

| mohs =

| luster = Vitreous

| streak = White

| diaphaneity = Transparent

| gravity = 3.292

| density =

| polish =

| opticalprop = Biaxial (-)

| refractive = nα = 1.599 - 1.619 nβ = 1.642 nγ = 1.661

| birefringence = δ = 0.062

| pleochroism =

| 2V = Measured: 84°

| dispersion =

| extinction =

| length fast/slow =

| fluorescence =

| absorption =

| melt =

| fusibility =

| diagnostic =

| solubility =

| impurities =

| alteration =

| other =

| prop1 =

| prop1text =

| references = [http://www.mindat.org/min-7192.html Niedermayrite on Mindat.org][http://webmineral.com/data/Niedermayrite.shtml Niedermayrite data on Webmineral]

}}

Niedermayrite is a rare hydrated copper cadmium sulfate hydroxide mineral with formula: Cu₄Cd(SO₄)₂(OH)₆·4H₂O. It crystallizes in the monoclinic system and occurs as encrustations and well formed vitreous blue-green prismatic crystals. It has a specific gravity of 3.36.

Niedermayrite was named for Gerhard Niedermayr (born 1941), an Austrian mineralogist affiliated with the Naturhistorisches Museum in Vienna, Austria. It was first described in 1998 from a mine in the Lavrion District, Attica, Greece. It is also reported from the Ophir District, Tooele County, Utah. The environment is in brecciated marble. The cadmium dominant analogue of campigliaite.