Valleriite

{{Short description|Uncommon sulfide-hydroxide mineral of iron and copper}}

{{infobox mineral

| name = Valleriite

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| image = Cubanite-Maucherite-Valleriite-199922.jpg

| imagesize = 260px

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| caption = Cubanite (brass yellow), maucherite (dark gray) and valleriite (dark bronze), mainly

| category = Sulfide mineral

| formula = {{chem2|(Fe(2+),Cu)4(Mg,Al)3S4(OH,O)6}}

| molweight =

| strunz = 2.FD.30

| dana = 2.14.1.1

| system = Trigonal

| class = Hexagonal scalenohedral ({{overline|3}}m)
H-M symbol: ({{overline|3}} 2/m)

| symmetry = R{{overline|3}}m

| unit cell = a = 3.79, c = 34.1 [Å]; Z = 2

| color = Bronze-yellow, gray

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| habit = Massive, nodular, encrustations, thin splintery

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| cleavage = Excellent on {0001}

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| mohs = 1–1.5

| luster = Metallic

| streak = Black

| diaphaneity = Opaque

| gravity = 3.14 (measured)

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| pleochroism = Strong; pale yellow to deep brown

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| references = [http://www.mindat.org/min-4136.html Valleriite on Mindat.org][http://rruff.info/doclib/hom/valleriite.pdf Handbook of Mineralogy][http://www.webmineral.com/data/Valleriite.shtml Valleriite data on Webmineral]

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Valleriite is an uncommon sulfide mineral (hydroxysulfide) of iron and copper with formula: {{chem2|4(Fe,Cu)S*3(Mg,Al)(OH)2}} or {{chem2|(Fe(2+),Cu)4(Mg,Al)3S4(OH,O)6}}. It is an opaque, soft, bronze-yellow to brown mineral which occurs as nodules or encrustations.