Editorial Feature

Bukovskyite - Occurrence, Properties, and Distribution

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Oct 21 2013

Image Credit: photominer/Shutterstock.com

Article updated on 06/03/20 by Kerry Taylor-Smith

Chemical Formula – Fe³⁺₂ (AsO₄)(SO₄)(OH)·7H₂O

Bukovskyite is an iron arsenate sulfate mineral that was discovered in 1967 near Kutna Hora, Czech Republic. It was named after the Czech chemist, Antonin Bukovsky, a professor of the secondary school at Kutna Hora, who first analyzed the mineral.

Properties of Bukovskyite

Bukovskyte forms nodules with a reniform or kidney-shaped surface. Under a microscope, the nodules appear as a collection of tiny needles akin to gypsum.

The following are the key properties of Bukovskyite:

Cell Data

Space Group: P1 or P1
a = 10.722(5)
b = 14.079(5)
c = 10.284(5)
α = 93.50(4)°
β = 115.96(4)°
γ = 90.27(4)°
Z = 4

Crystal Data

Triclinic, meaning the crystal has no symmetrical elements or only an inverse center. It typically has three unequal axes, where no two are perpendicular.
Point Group: 1 or 1 – this refers to the permutation of atoms, such that the crystal is transformed into a state indistinguishable to the starting state.
Crystals, needlelike, elongated along [011], to .5 mm, showing {0kl} forms, terminated by {100} and {302}, may be in radial groups; generally, n aggregates, forming nodules
X-ray Powder Pattern: 9.197 (100), 8.884 (60), 9.625 (43), 3.077 (36), 3.920 (35), 2.458 (23), 5.338 (20)

Chemical Composition

Elements	Content 1	Content 2
Fe₂O₃	32.42	32.6
H₂O	28.12	27.59
As₂O₅	22.1	23.46
SO₃	16.5	16.35
Total	99.14	100

Content 1: from Kank, Czech Republic; original total is given as 99.32%, presence of AsO₄, SO₄, and (OH)1− confirmed by IR; assuming H₂O− 0.69%, corresponds to Fe2.00(AsO₄)0.95(SO₄)1.02(OH)1.00 • 7H₂O.

Content 2: Fe₂(AsO₄)(SO₄)(OH) • 7H₂O.

Optical Properties

Optical Class: Biaxial; birefringence 0.049–0.056; very weak dispersion
Orientation: Extinction angle = 22°
α = n.d
β = 1.570–1.582 (β')
γ = 1.626–1.631 (γ')
2V(meas.) = n.d.
Semitransparent

Estimated Properties

.	.
Electron density	Bulk density (electron density)=2.33 g/cm³ note: Specific gravity of Bukovskyite =2.34 g/cm³
Photoelectric	PE_Bukovskyite = 17.10 barns/electron U= PE_Bukovskyite x ρ Electron density= 39.88 barns/cm³
Fermion index	Fermion index = 0.005 Boson index = 0.99
Radioactivity	Bukovskyite is not radioactive

How to Identify Bukovskyite

Bukovskyite can be identified as a greenish-gray, orange or light-yellow mineral with a yellowish-white streak and vitreous luster. The mineral exhibits earthy fractures and can be formed as needle-like crystals or fibrous structures. The density of the mineral is 2.34 g/cm³ and its hardness is 5 on the Mohs scale.

Global Distribution

Bukovskyite is distributed in the dumps and overgrown pit heaps of the Kuntery and other mines, Kank, 2.5 km north of Kutna Hora, Czech Republic. It was used for poisoning fieldmice and other field vermin and was once thought to be simply arsenic trioxide.