Kara Mine, Hampshire, Tasmania

Kara Mine, Hampshire, Tasmania

Introduction
A number of skarn type assemblages exist at the Kara Mine, near Hampshire, Northwest Tasmania. The skarns occupy a trough-like pendant within late Devonian red granite known as the Housetop Granite. At the Kara No.1, ore-grade scheelite mineralisation forms an irregularly-shaped blanket draped 15-25m above the granite. Between the skarn and the granite is a tungsten-poor, quartz-epidote reaction zone (Whitehead, 1990).
Open pit mining of scheelite has been in progress since 1977. Magnetite is also of economic importance.
Minerals

Actinolite Felted green mats

Allanite Minor amounts recorded in the associated granite (Whitehead, 1990)

Andradite Colours from very pale yellow, green, red, brown and black. Forms include pentagonal dodecahedron and combination of dodecahedron and trapezohedron

Anthoinite As a white powdery mixture with mpororoite pseudomorphing scheelite (Matsubara & Kato)

Bavenite Sprays of transparent colourless crystals with a thomsonite-like habit is a rare calcium beryllium silicate. These are associated with fluorite, pyrite and epidote.

Biotite Recorded in the associated granite (Whitehead, 1990)

Calcite As crystals in a variety of habits including: short hexagonal prisms; long hexagonal prisms with flat terminations; long hexagonal prisms with pyramidal terminations. Also as vein infillings in magnetite: white to clear, some with bright pink long-wave fluorescence; golden opening to mamillary surfaces in cavities.

Chalcopyrite

Danalite As red poorly crystalline masses. Possibly the source for the beryllium in bavenite.

Diopside Recorded by C. Whitehead

Epidote Transparent lustrous green crystals

Feldspar K-feldspar recorded in the associated granite (Whitehead, 1990)

Fluorapatite Minor amounts recorded in the associated granite (Whitehead, 1990)

Fluorapophyllite Clear very lustrous crystals may be fluorapophyllite

Fluorite Clear to deep purpleoctahedrons to 5mm in cavities with epidote, pyrite, ?actinolite, and bavenite. Also as druzy secondary colourless octahedral microcrystals in the same cavities. As pink to purple octahedrons enclosed in calcite. Also recorded as minor amounts in the associated granite (Whitehead, 1990).

Halloysite Light brown and earthy (Matsubara & Kato)

Hedenbergite

Horneblende Black fibrous crystals, species not yet determined.

Magnetite Black massive, bright crystals including octahedral, dull crystals to 20mm. Also recorded as minor amounts in the associated granite (Whitehead, 1990).

Malachite As blue-green to bright green rosettes

Molybdenite Small rosettes

Montmorillonite Yellowish green and earthy in "the old trench" (Matsubara & Kato)

Mpororoite As a white powdery mixture with Anthoinite pseudomorphing scheelite (Matsubara & Kato)

Plagioclase An30 recorded in the associated granite (Whitehead, 1990)

Prehnite As pale green botryoidal coatings - to be confirmed

Pyrite As cubes, cube-octahedra

Quartz Recorded in the associated granite (Whitehead, 1990). Found as crystals in cavities in magnetite.

Scheelite Mainly as blebs in magnetite to a few cm across, occasionally as white crystals

Stolzite Orange crystals with epidote

Titanite (Sphene) Crystals not dissolved when calcite etched suspected to be titanite (F. Doedens, pers. comm.). Also recorded as minor amounts in the associated granite (Whitehead, 1990).

Tremolite Fibrous brownish crystals with actinolite and a dark olive green radiating silicate thought to be tremolite

Vesuvianite Recorded by C. Whitehead and confirmed by XRD

Wollastonite

Zircon Minor amounts recorded in the associated granite (Whitehead, 1990)

References
Matsubara, S. & Kato, A., 1984, Mpororoite & Anthoinite from the Kara Mine, Tasmania, Mineralogical Magazine, 48, 397-400
Whitehead, C.H., 1990, Kara Scheelite-Magnetite Deposit, 10th Australian Geological Convention, Hobart 1990, Excursion Guide E2, "Tin & Tungsten Deposits & Related Devonian Granitoids", Geological Survey of Australia

Actinolite	Felted green mats
Allanite	Minor amounts recorded in the associated granite (Whitehead, 1990)
Andradite	Colours from very pale yellow, green, red, brown and black. Forms include pentagonal dodecahedron and combination of dodecahedron and trapezohedron
Anthoinite	As a white powdery mixture with mpororoite pseudomorphing scheelite (Matsubara & Kato)
Bavenite	Sprays of transparent colourless crystals with a thomsonite-like habit is a rare calcium beryllium silicate. These are associated with fluorite, pyrite and epidote.
Biotite	Recorded in the associated granite (Whitehead, 1990)
Calcite	As crystals in a variety of habits including: short hexagonal prisms; long hexagonal prisms with flat terminations; long hexagonal prisms with pyramidal terminations. Also as vein infillings in magnetite: white to clear, some with bright pink long-wave fluorescence; golden opening to mamillary surfaces in cavities.
Chalcopyrite
Danalite	As red poorly crystalline masses. Possibly the source for the beryllium in bavenite.
Diopside	Recorded by C. Whitehead
Epidote	Transparent lustrous green crystals
Feldspar	K-feldspar recorded in the associated granite (Whitehead, 1990)
Fluorapatite	Minor amounts recorded in the associated granite (Whitehead, 1990)
Fluorapophyllite	Clear very lustrous crystals may be fluorapophyllite
Fluorite	Clear to deep purpleoctahedrons to 5mm in cavities with epidote, pyrite, ?actinolite, and bavenite. Also as druzy secondary colourless octahedral microcrystals in the same cavities. As pink to purple octahedrons enclosed in calcite. Also recorded as minor amounts in the associated granite (Whitehead, 1990).
Halloysite	Light brown and earthy (Matsubara & Kato)
Hedenbergite
Horneblende	Black fibrous crystals, species not yet determined.
Magnetite	Black massive, bright crystals including octahedral, dull crystals to 20mm. Also recorded as minor amounts in the associated granite (Whitehead, 1990).
Malachite	As blue-green to bright green rosettes
Molybdenite	Small rosettes
Montmorillonite	Yellowish green and earthy in "the old trench" (Matsubara & Kato)
Mpororoite	As a white powdery mixture with Anthoinite pseudomorphing scheelite (Matsubara & Kato)
Plagioclase	An30 recorded in the associated granite (Whitehead, 1990)
Prehnite	As pale green botryoidal coatings - to be confirmed
Pyrite	As cubes, cube-octahedra
Quartz	Recorded in the associated granite (Whitehead, 1990). Found as crystals in cavities in magnetite.
Scheelite	Mainly as blebs in magnetite to a few cm across, occasionally as white crystals
Stolzite	Orange crystals with epidote
Titanite (Sphene)	Crystals not dissolved when calcite etched suspected to be titanite (F. Doedens, pers. comm.). Also recorded as minor amounts in the associated granite (Whitehead, 1990).
Tremolite	Fibrous brownish crystals with actinolite and a dark olive green radiating silicate thought to be tremolite
Vesuvianite	Recorded by C. Whitehead and confirmed by XRD
Wollastonite
Zircon	Minor amounts recorded in the associated granite (Whitehead, 1990)