Erik Klemetti posted today at Eruptions about komatiite, which is apropos, considering I just finished imaging some samples of that ultramafic volcanic rock. Have a look at three samples from Barberton Greenstone Belt here, each from the 3.27 Ga Weltevreden Formation:
Link GigaPan by Callan Bentley
Link GigaPan by Callan Bentley
Link GigaPan by Callan Bentley
And, while we’re at it, here’s one from the Red Lake Greenstone Belt (~3.0 Ga) in northwestern Ontario (sample courtesy of McGill’s Christie Rowe):
Link GigaPan by Callan Bentley
Explore that spinifex texture to your heart’s content – jagged olivine ‘chandeliers’ hanging down off the roof of the flow into its interior.