Nadorite

Doritonite
General
CategoryHalide mineral
FormulaPbSbO2Cl
IMA symbolNad
Strunz classification3.DC.30
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M Symbol: (2/m 2/m 2/m)
Space groupBmmb
Identification
ColorBrown, brownish-yellow, yellow
TwinningOn {101}, nearly perpendicular (91°45'), common
CleavageOn {010}, perfect
FractureUneven
Mohs scale hardness3+12 - 4
LusterAdamantine, Resinous
StreakWhite, yellow to yellowish white
DiaphaneityTranslucent
Density7
Refractive indexnα = 2.300 nβ = 2.340 - 2.350 nγ = 2.360 - 2.400
Birefringenceδ = 0.060 - 0.100
DispersionStrong
Alters toTo cerussite
References

Nadorite is a mineral with the chemical formula PbSbO2Cl. It crystallizes in the orthorhombic crystal system and is brown, brownish-yellow or yellow in color, with a white or yellowish-white streak.

Nadorite is named after Djebel Nador in Algeria, where it was first identified in 1870.