A cluster of pyrite crystals. The entire surface is covered in near-microscopic growth lines where new crystals were once beginning to form.

Hematite crystals sitting upon long edenite crystals. Mt Ngongotaha, Taupo Volcanic Zone, New Zealand.

Large osumilite crystal within a tridymite-lined miarolitic cavity. Mt Ngongotaha, New Zealand.

Electron microscope image showing striations on the face of a quartz crystal.

Pyrite cubes.

Phillipsite, Kulnura, Australia.

White mullite needles and hematite in a tridymite-lined miarolitic cavity. From Mt Ngongotaha, Taupo Volcanic Zone, New Zealand.

Small pseudobrookite crystal cluster on tridymite. From Mt Ngongotaha, Taupo Volcanic Zone, New Zealand.

Scanning Electron Micrograph of a titanite crystal sitting on a hematite crystal. A secondary phase of hematite growth forms triangular spirals around the titanite. From Mt Ngongotaha, Taupo Volcanic Zone, New Zealand.

Scanning Electron Micrograph of clustered hematite crystals, measuring approximately 1mm across. From Mt Ngongotaha, Taupo Volcanic Zone, New Zealand.

Karijini National Park, Western Australia.

Translucent phlogopite mica inside a tridymite-filled miarolitic cavity. Mt Ngongotaha, Taupo Volcanic Zone, New Zealand.

Iridescent fayalite crystal on tridymite. Mt Ngongotaha, Taupo Volcanic Zone, New Zealand.

Tiny, bladed crystals of pseudomalachite from Suloga, PNG.

Karijini National Park, Western Australia.

(pseudomalachite from Suloga, PNG)

Patchwork blanket calcite from Western Australia, as seen in thin section under cross-polarised light.