Stolzite Stolzite, Broken Hill, Australia (size: 3.6 x 3.0 x 2.6 cm)
Category Tungstate minerals Formula (repeating unit) PbWO4 IMA symbol Sz[ 1] Strunz classification 7.GA.05 Crystal system Tetragonal Crystal class Dipyramidal (4/m) H-M symbol : (4/m) Space group I 41 /aUnit cell a = 5.461, c = 12.049 [Å]; Z = 4 Color Reddish brown, brown, yellowish gray, smoky gray, straw-yellow, lemon-yellow; may be green, orange, red Crystal habit Crystals dipyramidal to tabular Cleavage Imperfect on {001}, indistinct on {011} Fracture Conchoidal to uneven Tenacity Brittle Mohs scale hardness 2.5–3 Luster Resinous, subadamantine Streak White Diaphaneity Translucent to transparent Specific gravity 8.34 Optical properties Uniaxial (−) Refractive index nω = 2.270 nε = 2.180 – 2.190 Birefringence δ = 0.090 References [ 2] [ 3] [ 4] [ 5]
Stolzite is a mineral , a lead tungstate ; with the formula PbW O 4 . It is similar to, and often associated with, wulfenite which is the same chemical formula except that the tungsten is replaced by molybdenum . Stolzite crystallizes in the tetragonal crystal system and is dimorphous with the monoclinic form raspite .[ 4]
Stolzite crystal from the Darwin District, Inyo County, California (size: 2.0 × 1.7 × 1.6 cm)
Lead tungstate crystals have the optical transparency of glass combined with much higher density (8.28 g/cm3 vs ~2.2 g/cm3 for fused silica ). They are used as scintillators in particle physics because of their short radiation length (0.89 cm), low Molière radius (2.2 cm), quick scintillation response, and radiation hardness.[ 6] Lead tungstate crystals are used in the Compact Muon Solenoid's electromagnetic calorimeter.[ 6]
It was first described in 1820 by August Breithaupt , who called it Scheelbleispath and then by François Sulpice Beudant in 1832, who called it scheelitine. In 1845, Wilhelm Karl Ritter von Haidinger coined the name stolzite for an occurrence in the Ore Mountains , Bohemia (today the Czech Republic ), naming it after Joseph Alexi Stolz of Teplice in Bohemia.[ 4] [ 5] It occurs in oxidized hydrothermal tungsten-lead ore deposits typically in association with raspite , cerussite , anglesite , pyromorphite and mimetite .[ 3]
See also
References
Mellor, J. W. "A Comprehensive Treatise on Inorganic and Theoretical Chemistry," Vol.11, Longmans, Green and Co., London, 1931, p. 792.
Wikimedia Commons has media related to
Stolzite .