Lord Brassey Mine fossicking area
Access and Collecting Area
The Lord Brassey mine is located on Brassey Hill, about 17 km west of Waratah in western Tasmania. Access to the 0.6 km2 fossicking area is via a very rough and steep four-wheel drive track heading north from Waratah Road, about 300 hundred metres west of the Heazlewood River picnic area. The mine is reached after travelling approximately 1.5 km along the 4WD track. Most fossicking is done on the dump adjacent to the mine (adit) entrance close to the top of the hill, at approximately AMG reference 359 300 mE, 5 408 500 mN.
The Mine and its Minerals
This small mine operated on a nickel sulphide occurrence in ultrabasic rocks (serpentinite and pyroxenite). The sulphide ores probably formed during deformation of these rock types, and later weathering converted some of the sulphides into carbonates. Minerals, many rare, that can be collected and identified in hand specimens include:
Andradite Ca3Fe2(SiO4)3 - `chrome' green veinlets in serpentine.
Antigorite Mg3Si2O5(OH)4 - apple green serpentine.
Awaruite (Ni,Fe) - metallic white, rusty.
Chrysotile Mg3Si2O5(OH)4 - white, asbestiform serpentine.
Clinochlore Mg6(Si,Al)4O10(OH)8 - chlorite, dark green.
Diopside CaMgSi2O6 - white veins in serpentine.
Dypingite Mg5(CO3)4(OH)2.5H2O - pale blue to white, botryoidal crusts on serpentine.
Heazlewoodite Ni3S2 - bronzy yellow metallic patches in serpentine.
Hellyerite NiCO3.6H2O - pale blue coatings and small crystals, <2 mm.
Lizardite Mg3Si2O5(OH)4 - black serpentine.
Magnetite Fe3O4 - small black grains, in serpentine.
Molybdenite MoS2 - small patches of massive dark grey to occasionally purple grey.
Opal SiO2 - glassy veinlets in serpentine.
Pentlandite (Fe,Ni)9S8 - brassy yellow metallic patches in serpentine.
Reevesite Ni6Fe23+(CO3)(OH)16.4H2O - a lemon yellow crust on sulphides in serpentine.
Retgersite NiSO4.6H2O - pale to mid blue, powdery crusts.
Theophrastite Ni(OH)2 - a green crystalline crust on slickensided serpentine.
Zaratite Ni3(CO3)(OH)4.4H2O - emerald green, blue green and olive green coatings and mammillary, stalactitic or amorphous encrustations along the shear planes and joint surfaces of the serpentine.
- Historic mining relics occur in this area. Fossickers are asked to respect these relics by avoiding disturbance of historic workings and not collecting artefacts (e.g. bottles, pieces of machinery, etc.) from this area.
- UNDER NO CIRCUMSTANCES should fossickers enter the disused adit.