en Vrbaite - 2025

Vrbaite
Vrbaïte, Crven Dol Mine, Allchar (Alsar), Roszdan, North Macedonia
General
Category	Mineral
Formula (repeating unit)	Tl4Hg3Sb2As8S2
Strunz classification	02.HF.20 2 SULFIDES and SULFOSALTS (sulfides, selenides, tellurides; arsenides, antimonides, bismuthides; sulfarsenites, sulfantimonites, sulfbismuthites, etc.) 2.H Sulfosalts of SnS Archetype 2.HF With SnS and PbS archetype structure units 2.HF.20 Vrbaite Tl4Hg3Sb2As8S20 Space Group C mca Point Group 2/m 2/m 2/m
Dana classification	03
Crystal system	orthorhombic
Crystal class	Dipyramidal ; $C$ $mca$ {C 2/m 2/c 2 India/a}
Identification
Color	black, gray-black, bluish, dark red; on polished sections, bluish white with internal red highlights
Fracture	uneven/irregular to conchoidal
Tenacity	3,5
Density	5,27-5,33
Refractive index	n = 2,72-2,73
Dispersion	r > v
Ultraviolet fluorescence	aucune
Absorption spectra	opaque

Vrbaite (symbol: Vrb) is an opaque to subtranslucent brittle mineral with chemical formula Tl₄Hg₃Sb₂As₈S₂₀ and pyramidal crystals. It is names after Czech mineralogist Karel Vrba [cs]. It is bluish white with red internal reflections and dark red in translucent thin fragments. It is classified in the class "sulfides and sulfosalts".^[1]^[2]

Type locality: Allchar deposit, Ržanovo mine [mk], Kavadarci Municipality, North Macedonia.^[2]^[3]

References

v t e IMA–CNMNC / Nickel–Strunz IDs Mineral categories (classes, subclasses, divisions)
"Special cases" ("native elements and organic minerals")	"Native elements" (IDs 1) Organic minerals (IDs 10)
"Sulfides and oxides"	Sulfides (IDs 2.A–F) Sulfosalts; sulfarsenites, sulfantimonites, sulfbismuthites (IDs 2.G) Sulfosalts; sulfarsenates, sulfantimonates (IDs 2.K) Other sulfosalts (IDs 2.H–J and 2.L–M) Oxides (IDs 4.A–E, e.g. pyrochlore supergroup and corundum group) Hydroxides (IDs 4.F–G) Arsenates(IV), sulfates(IV) and iodates (IDs 4.J–K) Tellurium oxysalts Vanadium oxides (IDs 4.H)
"Evaporites and similars"	Carbonates (IDs 5.A–E) Nitrates (IDs 5.N) Borates (IDs 6) Halides (IDs 3)
"Mineral structures with tetrahedral units" (sulfate anion, phosphate anion, silicon, etc.)	Monomeric minerals (similar to nesosilicates) Sulfates(VI) (IDs 7.A–E) Thiosulphates (IDs 7.J) Chromates(VI) (IDs 7.F) Molybdates, wolframates, niobates(VI) (IDs 7.G–H) Phosphates(V) (IDs 8) Arsenates, vanadates(V) (IDs 8) Monomeric, isolated silicates (IDs 9.A) Germanates (IDs 9.J) Silicate frameworks, tectosilicates Zeolite frameworks, zeolite family (IDs 9.G) Other feldspathoids: nephelines (IDs 9.FA.05) Cancrinite-sodalite groups (IDs 9.FB.) Other tectosilicates (IDs 9.FA. and 9.FB.15, e.g. feldspars) Other silicate frameworks Cyclosilicates (IDs 9.C) Phyllosilicates (IDs 9.E, e.g. clays) Silica family (IDs 4.DA.) Inosilicates Single chain inosilicates (IDs 9.D, e.g. pyroxenes) Ribbon or multiple chain inosilicates (IDs 9.D, e.g. amphiboles) Other non monomeric minerals Unclassified silicates (IDs 9.H) Sorosilicates (IDs 9.B, e.g. epidote and seidozerite supergroups) Polymeric, isolated silicates (IDs 9.A, e.g. olivine and gadolinite supergroups) Other inorganic polymers (e.g. polyoxometalates; "polyphosphates", IDs 8.F)
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