Curite

Curite
Orange-red curite needles from Shinkolobwe mine, Katanga Province, Democratic Republic of the Congo
General
CategoryOxide mineral
Formula
(repeating unit)
Pb3[(UO2)4|O4|(OH)3]2·2 H2O[1]
IMA symbolCui[2]
Strunz classification4.GB.55
Crystal systemOrthorhombic
Crystal classorthorhombic-dipyramidal; 2/m 2/m 2/m[3]
Space groupPnam[4]
Unit cella = 12.551 Å, b = 13.02 Å,
c = 8.40 Å; Z = 2
Identification
Colorred, reddish orange, brownish yellow.
Crystal habitneedles, acicular, massive, compact earthy.
Cleavage{100}, imperfect}[5]
Fractureuneven
Tenacitybrittle
Mohs scale hardness4-5
Lusteradamantine
Streakorange
Diaphaneitytransparent
Densitymeasured: 6.98–7.4; calculated: 7,37[5]
Optical propertiesbiaxial (-)
Refractive indexnα = 2.060 nβ = 2.110 nγ = 2.150[6]
Birefringence0.090
PleochroismVisible: X = b = pale yellow, Y = a = light red-orange, Z = c = dark red-orange
2V angle70° (measured); 80° (calculated)[6]
Other characteristics Radioactive

Curite is a rare mineral with the chemical composition Pb3[(UO2)4|O4|(OH)3]2·2 H2O.[1] It is therefore a hydrated lead uranyl oxide, which forms red needles or orange, massive aggregates.

  1. ^ a b Cite error: The named reference Lapis was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Warr was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Webmineral was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference AMCSD was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Handbookofmineralogy was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Mindat was invoked but never defined (see the help page).