The system Pd–Ag–S: phase relations and mineral assemblages. (10th February 2020)

• Record Type: Journal Article
• Authors: Vymazalová, Anna; Laufek, František; Kristavchuk, Alexandr V.; Chareev, Dmitriy A.
• Is Part Of: Mineralogical magazine. Volume 84:Number 1(2020)
• Page Start: 125
• Page End: 130
• Publication Date: 2020-02-10
• Subjects: Pd–Ag–S system, -- phase relations, -- phase diagram, -- platinum-group minerals, -- coldwellite, -- kravtsovite, -- vysotskite, -- vasilite, -- phase Pd13Ag3S4; Mineralogy -- Periodicals; Mineralogy -- Great Britain -- Periodicals; 549.05
• DOI: 10.1180/mgm.2020.1
• Languages: English
• ISSNs: 0026-461X

Abstract

Abstract: Phase equilibria in the system Pd–Ag–S were studied using the silica-glass tube method at 400°C and 550°C. In the system we synthesised three ternary phases: coldwellite (Pd3 Ag2 S), kravtsovite (PdAg2 S) and a new phase Pd13 Ag3 S4 . At 400°С, coldwellite forms a stable association with vysotskite (PdS) and vasilite (Pd16 S7 ); vysotskite and kravtsovite; phase Pd4 S and a Ag–Pd alloy; it also coexists with a new phase Pd13 Ag3 S4 . Kravtsovite is stable up to 507°C; the presence of kravtsovite in the mineral assemblage reflects its formation below this temperature. The occurrence of coldwellite, vysotskite and Ag2 S together in equilibrium reflects the formation of this mineral assemblage above this temperature (507°C). Coldwellite is stable up at 940°С. Mineral assemblages defined in this study can be expected in Cu–Ni–PGE mineral deposits, associated with mafic and ultramafic igneous rocks, in particular in mineralisations with known silver–palladium sulfides.