Tiny rhombs of colourless calcite with opaque white laumontite on fibrous mordenite. Laumontite, Mordenite, Calcite, Waitekauri, Hauraki District, Waikato Region, North Island, New Zealand. Width of view 11mm.
Tucked away in a quiet valley in the Coromandel Peninsula, the area around Waitekauri is now a peaceful landscape of regenerating bush, but its ghostly remnants of mining machinery tell a story of immense gold rush fever. In the late 19th century, this was a booming town and one of...
Hokitika was founded during the West Coast gold rushes in 1864. Examples of gold from the local rivers can be purchased at tourist shops. Below: Gold, Hokitika, Westland District, West Coast Region, New Zealand. Nugget measures 8mm across.
Hokitika, on the west coast of the South Island, is a town whose entire identity, from its deep Māori history to its explosive European settlement, is inextricably linked to its unique geology and mineral wealth. 1. The Geological Setting: An Engine of Creation and Erosion The geology of the Hokitika...
Hokitika was founded during the West Coast gold rushes in 1864. Examples of gold from the local rivers can be purchased at tourist shops. Below: Gold, Hokitika, Westland District, West Coast Region, New Zealand.
Siderite is a very common mineral, in lustrous or iridescent deep brown forms, rarely in paler brown translucent balls. Generally it is in sheaf-like bundles, occasionally in ‘bow-ties’. It does occur in rhombs, often with curved multiple surfaces, and these are frequently hollow, with maybe a chabazite or two inside....
Siderite is a very common mineral, in lustrous or iridescent deep brown forms, rarely in paler brown translucent balls. Generally it is in sheaf-like bundles, occasionally in ‘bow-ties’. It does occur in rhombs, often with curved multiple surfaces, and these are frequently hollow, with maybe a chabazite or two inside....
Phillipsite has been found as crystals in the classic phillipsite form as larger (1mm) crackled clear crystals, associated with barite and clear barrel-shaped chabazite. It also occurs as minute creamy crystals with analcime and chabazite, also small. The exact species has not been confirmed. Below: Phillipsite, Bickers Quarry (Simpkins Quarry),...
Black magnetite octahedra, some with traces of chlorite on their faces, some of which are stepped. Some magnetite crystals are completely encased in chlorite. Blocky orthoclase crystals form part of the cavity lining. Brown sheaf or club-shaped siderite, yellow hexagonal chabazite-Na, and needles of apatite coated with chlorite. Below: Magnetite,...
Gypsum tends to usually occur alone or with barite, chabazite-Na and analcime in the more weathered rock. It forms sprays of clear needles, or larger flat crystals. Below: Gypsum, chabazite-Na, Bickers Quarry (Simpkins Quarry), Tokatoka, Kaipara District, Northland Region, North Island, New Zealand. Width of view 6mm.
Gypsum tends to usually occur alone or with barite, chabazite-Na and analcime in the more weathered rock. It forms sprays of clear needles, or larger flat crystals. Below: Gypsum, siderite and chlorite, Bickers Quarry (Simpkins Quarry), Tokatoka, Kaipara District, Northland Region, North Island, New Zealand. Width of view 6mm.
Chabazite-Na (“herschelite“) crystals are found in many vugs, as single yellowish, cream, white or colourless hexagonal plates, with striated prism faces and matt-finish flat surfaces. Under magnification the flat surfaces are shown to be made of many tiny points. These crystals are splendid examples of the “herschelite” crystal shape, and...
Barite occurs as white tabular plates or rosettes, on chlorite and in weathered zones, and as chunky white bipyramids. Barite can be found with chabazite, gypsum, analcime, and harmotome-phillipsite. Below: Pseudohexagonal Barite, Bickers Quarry (Simpkins Quarry), Tokatoka, Kaipara District, Northland Region, North Island, New Zealand. Width of view 3mm.
Chabazite-Na (“herschelite“) crystals are found in many vugs, as single yellowish, cream, white or colourless hexagonal plates, with striated prism faces and matt-finish flat surfaces. Under magnification the flat surfaces are shown to be made of many tiny points. These crystals are splendid examples of the “herschelite” crystal shape, and...
Apatite occurs as fine needles, often coated with brown chlorite. Occasionally it is strung with tiny “herschelite” (chabazite-Na) crystals. Below: Prismatic coated apatite crystal with yellow hexagonal chabazite-Na and orange chlorite. Width of view 6mm.
Analcime is found as small water-clear trapezohedra, occasionally with white cores, and often with square c-faces. Larger crystals are usually crackled and clouded. It is associated with most other minerals, but less common in vugs, and analcime is the mineral most likely to be found coating old fractures. Below: Three...
Analcime is found as small water-clear trapezohedra, occasionally with white cores, and often with square c-faces. Larger crystals are usually crackled and clouded. It is associated with most other minerals, but less common in vugs, and analcime is the mineral most likely to be found coating old fractures. Below: Unidentified...
Bickers Quarry (originally described as Simpkins Quarry) has been owned by Mr. S. Bicker. It is on the north side of Tokatoka Road, a short way east of the junction with Simpkin Road, about 3.5km northeast of Tokatoka (Fig 1 and Fig 2). Tokatoka is about 15km southeast of Dargaville...
Octahedral magnetite crystals with yellowish chabazite and dark brown siderite. Chabazite-Na (“herschelite“) crystals are found in many vugs, as single yellowish, cream, white or colourless hexagonal plates, with striated prism faces and matt-finish flat surfaces. Under magnification the flat surfaces are shown to be made of many tiny points. These...
Calcite is abundant, and often is the only mineral in a cavity. It generally grows directly on the vugh walls, but also occurs on phillipsite, and may have phillipsite, erionite or barite growing on it. Perhaps the commonest form is clear to white “castles” of a rounded tapering crystal with...
Quartz occurs as small prismatic crystals or drusy coatings on other minerals. There are also seams of agate at Moeraki Point. Below: Small colourless quartz on white calcite, on brown nontronite(?), Moeraki Point Quarry, Otago, New Zealand. Width of view 11.5mm. Ex Jo Price Collection.
Twinned phillipsite crystals on and with calcite. Ex Jo Price Collection. Below: Phillipsite on calcite, Moeraki Point, Otago, New Zealand. Width of view 5.75mm.
These crystals were noted early in investigations, and were thought of as aragonite sixlings. However Ruth Jacobsen sent some specimens to William Henderson who wrote up the mineral in the Mineralogical Record, Vol 14, No 1, 1983. “It was immediately sight-identifiable as erionite, being identical in crystal form to that...
Phillipsite is very common at Moeraki. It may occur as large single crystals or clusters with distinctive cross-hatching on the faces. Water-clear balls of phillipsite are very common, recognised by the four sides to each point on the ball. These balls often have a milky centre or a hollow core....
Moeraki Point (also known as the Moeraki Headland) is the rocky promontory that forms the southern arm of the bay where the Moeraki Boulders are found, in the Otago region of New Zealand. While the boulders are a sedimentary phenomenon, the point itself is volcanic. The rocks at Moeraki Point...
These crystals were noted early in investigations, and were thought of as aragonite sixlings. However Ruth Jacobsen sent some specimens to William Henderson who wrote up the mineral in the Mineralogical Record, Vol 14, No 1, 1983. “It was immediately sight-identifiable as erionite, being identical in crystal form to that...
Below: White-colourless zoned barite, with dark brown siderite, Bickers Quarry (Simpkins Quarry), Tokatoka, Kaipara District, Northland Region, North Island, New Zealand. Width of view 3mm.
