Arthurite is a mixture of divalent copper and iron ions in combination with trivalent arsenate, sulfate and phosphate ions. The mineral was first discovered by Sir Arthur Russell in 1954 at Hingston Down Consols mine in Calstock, Cornwall, England.
It was named after Sir Arthur Edward Ian Montagu Russell and Arthur William Gerald Kingsbury for their contributions to British mineralogy.
Properties of Arthurite
The following are the key properties of Arthurite:
- Cell Data
- Space Group: P21/c
- a = 10.189(2)
- b = 9.649(2)
- c = 5.598(1)
- β = 92.16(2)°
- Z = 2
- Crystal Data
- Point Group: 2/m
- As prismatic to acicular crystals, to 5 mm; usually as spherical aggregates and thin crusts
- X-ray Powder Pattern: 4.28 (vvs), 4.81 (vvs), 6.97 (vvs), 10.08 (vs), 2.801 (vs), 2.912 (s), 3.44 (ms)
- Chemical Composition
- Optical Properties
- Optical Class: Biaxial (+), may be biaxial (–)
- Pleochroism: X = colorless to pale green; Y = gray-green; Z = olive-green
- Orientation: Y = b; Z ^ c = 10°
- Absorption: Z > Y > X.
- α = 1.736
- β = 1.767
- γ = 1.796
- 2V(meas.) = ~90°
- Estimated Properties
||Bulk density (electron density)=3.17 g/cm3
note: Specific gravity of Arthurite =3.28 g/cm3
||PEArthurite = 25 barns/electron
U= PEArthurite x ρ Electron density= 79.27 barns/cm3
||Fermion index = 0.004
Boson index = 0.99
||Arthurite is not radioactive
How to Identify Arthurite
Arthurite can be observed in emerald green or green. It has transparent appearance, vitreous luster and light green streak. Its fractures are brittle and it can be formed as spherical, rounded aggregates or needle-like or prismatic crystals. The mineral has a density of 3.02 g/cm3, and hardness ranging from 3 to 4.
Arthurite is distributed in the following places:
- Hingston Down Consols mine, Calstock, Cornwall
- St. Austell, and the Cligga Head mine, Perranzabuloe
- Clara mine, near Oberwolfach, Black Forest, Germany
- Bendada pegmatite, near Guarda, Portugal
- Rodalquilar, Almeria Province, Spain
- Potrerillos mine, Atacama, Chile
- Majuba Hill mine, Antelope district, Pershing Co., Nevada
- Black Pine mine, near Philipsburg, Granite Co., Montana
- Gold Hill, Tooele Co., Utah, USA
- Dome Rock copper mine, about 40 km northwest of Mingary, South Australia.
Occurrence of Arthurite and Useful Mineral Association
Arthurite occurs as a rare secondary mineral in the oxidized zone of some copper deposits that are formed by alteration of arsenopyrite or enargite. It is closely associated with quartz, brochantite, chalcophyllite, chenevixite, conichalcite, scorodite and pharmacosiderite.