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Formula: Ag3Pb6(Sb8Bi3)S24
Sulphosalt, lillianite homologous series,
antimony- and bismuth-
bearing mineral
Crystal System: Monoclinic
Specific gravity: 5.899 calculated for the empirical formula and 5.905 calculated for the ideal formula
Streak: Grey
Colour: Steel-grey
Luminescence: No fluorescence under UV
Environments
Holubite is a new mineral, approved in 2023 and to date (August 2023) reported only from the type locality.
Localities
At the type locality, the Staročeské Lode, Kutná Hora, Kutná Hora District, Central Bohemian Region, Czech Republic,
the ore district contains a hydrothermal vein type mineralisation of Variscan age (~ 270 million years ago). Each
lode represents a hydrothermally altered zone of several hundred metres to ∼3 km in length and dozens of metres wide,
with the depth ranging between several hundred metres to 1 km, each consisting of several, usually parallel veins.
Two mineral assemblages are present in this ore district, one silver-rich in
the southern part of the ore district and one pyrite-rich in the northern
part. The Staročeské pásmo Lode belongs to the northern pyrite-rich lodes and
is the biggest lode of the Kutná Hora ore district.
The samples were collected in the material from medieval mine dumps, but more recent mining in the second half of the
16th Century revealed a silver-rich base-sulphide vein formed mainly of
massive pyrite, pyrrhotite,
marcasite, chalcopyrite,
arsenopyrite, sphalerite
and stannite, up to two metres thick, and the newly found material from this
mining made it possible to study the mineralogical composition of the massive
silver-rich pyrite ores (not present
on the medieval dumps), next to silver –
bismuth mineralisation in quartz
gangue without massive sulphides, which can occasionally be found on mediaeval
mine dumps.
The holotype hand sample is formed of white coarse-grained quartz with silvery
grey metallic lenses and grains of silver,
bismuth-bearing galena and
silver - bismuth sulphosalts
(including holubite, terrywallaceite,
eskimoite and treasurite) up
to 3 mm across with no base sulphides.
The holubite occurs most frequently as replacement rims and grain aggregates of earlier
silver – lead –
bismuth minerals, growing together in aggregates up to 200 × 50 μm. It
commonly occurs in a close association with silver- and
bismuth- bearing galena and
terrywallaceite. It is assumed that the holubite is a
replacement product of earlier galena and
lillianite homologues, richer in
bismuth, in line with a general succession trend observed in the
silver – lead –
bismuth – antimony mineralisation
in the Kutná Hora ore district being from bismuth-rich to
antimony-rich minerals.
(MM 87.582–590).
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