Shapes of Nature

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Reticulite is like glass in rock form… A frothy volcanic rock that forms during vigorous fire-fountaining of lava. It is so full of bubbles that it floats on water. It is like very fine pumice made of glass, and has the lowest density of any rock, with a porosity of up to 98 percent. The open honeycomb network of bubbles (vesicles) results from the bursting of cell walls against one another during vesiculation. I got a small sample of this silicate rock from a colleague in geophysics, and mounted it with doubled-sided tape in a paper slide. One really needs to see this in 3 dimensions and the structure is so fragile, that compression between slides or tape breaks the glass-like skeleton, but still allowed me to see the pores and pillars of the reticulate structure. Patterns of nature in glass… from a volcano!

2 Comments Add yours

  1. Manu Prakash says:

    Remarkable. I had never heard of this rock before – although the Hawaiian rocks always come to mind. It’s so clear that a series of foam forming processes might be at play here from your images. This is such an exciting post.

    How light is the rock? Would it really float on water? The reason I ask is slightly whimsical – I know of a story in Indian Mythology where rocks floated on water. I wonder if it was a volcanic rock 🙂

    Fantastic work. Please continue sharing your passion on the site.


  2. Lydia-Marie Joubert says:

    Yes, volcanic rocks do float, it’s all embedded in their density. Rocks like pumice are indeed ‘frozen foam’ filled with air bubbles. If we paid more attention to mythology, maybe science would be more holistic! Our ancestors’ tales are a treasure trove of hidden wisdom…

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