Image
This close-up of a black smoker hydrothermal chimney spire shows copper-rich chalcopyrite crystals (yellow) and zinc-rich sphalerite (grey) near its margins. These different minerals reflect different temperatures within the chimney. Chalcopyrite indicates temperatures greater than 300ºC, whereas sphalerite indicates lower temperatures.
Te whakamahi i tēnei tūemi
by Alastair McLean
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