Kasolite

Kasolite
Kasolite and malachite from Musonoi mine, Democratic Republic of Congo
General
Category	Mineral
Formula (repeating unit)	Pb(UO2)(SiO4) · H2O
IMA symbol	Kso
Strunz classification	09.AK.15
Dana classification	53.03.01.01
Crystal system	Monoclinic
Crystal class	Prismatic H-M symbol: 2/m
Space group	P 21/a
Unit cell	596.48
Identification
Formula mass	587.33
Color	Reddish orange, yellow, yellow brown, green, gray green
Cleavage	Perfect on {001} Good on {010}, {100}
Fracture	Uneven
Tenacity	Brittle
Mohs scale hardness	4 - 5
Luster	Resinous, Greasy
Streak	Light brownish yellow
Diaphaneity	Transparent, translucent, opaque
Specific gravity	5.83 - 6.5
Density	Measured: 5.83 - 6.5 Calculated: 6.256
Optical properties	Biaxial (+)
Refractive index	nα = 1.890 nβ = 1.910 nγ = 1.950
Birefringence	0.060
Pleochroism	Weak X =Y = Pale yellow Z = Colorless to slightly grayish
2V angle	Measured: 43° Calculated: 72°
Dispersion	Strong
Ultraviolet fluorescence	Radioactive
Common impurities	As, P, Ba, Fe, Mg, Ca
Other characteristics	Radioactive

Kasolite is an uncommon lead uranyl silicate monohydrate mineral. It is an IMA approved mineral, that had been a valid species before the foundation of the association, that had been first described and published in 1921 by Schoep. It is a grandfathered mineral, meaning the name kasolite is still believed to refer to a valid species to this day. The mineral's name originates from its type locality, namely the Shinkolobwe Mine, also known as Kasolo Mine. Kasolite is possibly the lead analogue of the unnamed phase UM1956-02-SiO:CaHU, and it is the only accepted lead-uranium silicate.^[1]