Stolzite

Stolzite is a mineral, a lead tungstate; with the formula PbWO₄. 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.[3]

Stolzite
Stolzite, Broken Hill, Australia (size: 3.6 x 3.0 x 2.6 cm)
General
Category	Tungstate minerals
Formula (repeating unit)	PbWO4
Strunz classification	7.GA.05
Crystal system	Tetragonal
Crystal class	Dipyramidal (4/m) H-M symbol: (4/m)
Space group	I41/a
Unit cell	a = 5.461, c = 12.049 [Å]; Z = 4
Identification
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	[1][2][3][4]

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.[5] Lead tungstate crystals are used in the Compact Muon Solenoid's electromagnetic calorimeter.[5]

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 Krusne Hory (Erzgebirge), Czech Republic, naming it after Joseph Alexi Stolz of Teplice in Bohemia.[3][4] It occurs in oxidized hydrothermal tungsten-lead ore deposits typically in association with raspite, cerussite, anglesite, pyromorphite and mimetite.[2]

See also

• List of minerals
• List of minerals named after people

References

1. Mineralienatlas
2. Handbook of Mineralogy
3. Mindat.org
4. Wevmineral data
5. The CMS Collaboration (2006). "Chapter 1. Introduction". CMS Physics : Technical Design Report Volume 1: Detector Performance and Software. CERN. p. 14. ISBN 9789290832683. CMS has chosen lead tungstate scintillating crystals for its ECAL. These crystals have short radiation (X0 = 0.89 cm) and Moliere (2.2 cm) lengths, are fast (80% of the light is emitted within 25 ns) and radiation hard (up to 10 Mrad).

Mellor, J. W. "A Comprehensive Treatise on Inorganic and Theoretical Chemistry," Vol.11, Longmans, Green and Co., London, 1931, p. 792.

Stolzite crystal from the Darwin District, Inyo County, California (size: 2.0 x 1.7 x 1.6 cm)