Weilite
Weilite (CaHAsO4) is a rare arsenate mineral. It is a translucent white triclinic mineral with a waxy luster.[2]
| Weilite | |
|---|---|
|  Weilite (white) with pink erythrite from Richelsdorf District, Wildeck, Hesse, Germany | |
| General | |
| Category | Arsenate mineral | 
| Formula (repeating unit) | CaHAsO4 | 
| IMA symbol | Wei[1] | 
| Strunz classification | 8.AD.10 | 
| Crystal system | Triclinic | 
| Crystal class | Pinacoidal (1) (same H-M symbol) | 
| Space group | P1 | 
| Unit cell | a = 7.059 Å, b = 6.891 Å c = 7.201 Å; α = 97.43° β = 103.55°, γ = 87.75°; Z = 4 | 
| Identification | |
| Color | White | 
| Crystal habit | Powdery, massive | 
| Fracture | Irregular/uneven | 
| Tenacity | Brittle | 
| Luster | Waxy, greasy, dull | 
| Streak | White | 
| Diaphaneity | Translucent | 
| Specific gravity | 3.48 | 
| Optical properties | Biaxial (-) | 
| Refractive index | nα = 1.644 nγ = 1.688 | 
| Birefringence | δ = 0.044 | 
| 2V angle | Measured: 81° | 
| References | [2][3][4] | 
It was first described in 1963 for occurrences in Gabe Gottes Mine, Haut-Rhin, Alsace, France; Wittichen, Schenkenzell, Black Forest, Baden-Württemberg, Germany; and the Schneeberg District, Erzgebirge, Saxony, Germany. It is named after French mineralogist René Weil of the University of Strasbourg.[2] It occurs in the oxidized zone of arsenic-bearing hydrothermal veins. It occurs as an alteration product of pharmacolite and haidingerite.[3][4]
References
    
- Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- Mindat.org
- Handbook of Mineralogy
- Webmineral data
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