1. Since ancient times, rocks and minerals have been highly valued, with
gems, semi-precious stones and slabs of marble and granite being cut
and polished and used lavishly in the very finest artefacts, architecture
and jewellery. On a much more modest scale, there are surely very
few households where an attractive pebble, mineral, fossil or rock,
picked up from a beach, can’t be found.
However, one of the most spectacular ways of displaying the inherent
natural beauty of rocks and minerals is very rarely seen outside
universities and analytical laboratories.
In 1849, Henry Sorby of Sheffield pioneered a new branch of geology –
“Microscopical Petrography” – a technique of examining thin sections
of rock, only a thousandth of an inch, using plane and polarised light.
Considered a source of great amusement at the time, especially by the
Swiss geologist Saussure who thought it “especially ridiculous to look
at mountains through a microscope”, the technique is now widely
accepted by geologists as an essential tool for studying rocks.
When polarised light is shone through these rock thin sections, it is
refracted by the internal crystallographic structure of the minerals to
produce an astonishing array of vivid colours which vary according to
both the chemical composition and orientation of the individual
interlocking crystals. Although this microscopic technique is primarily
used to identify minerals and help the geologist to understand how
rocks are formed, the subject material inspired John Ruskin, a friend of
Sorby and mineral collector, to write lyrically of the beauties to be seen.
Using photography and digital technology to take the subject matter to
another level, the saturated colours and repetitive forms have been since
described as “resembling the abstract graphics for a psychedelic trance
party flyer, with an overall effect that is bizarrely futuristic”.
stonestone
A New Way of
Looking at Stone
by Scott Engering Geologist & Building Stone Consultant - Contributing European Editor
Main picture LHERZOLITE: deep fractures in the Earth reflect surface structures.
Figure 2: Graphic Granite, these inter-twining crystal structures were well known to
the Egyptians.
Figure 3: Olivine, crystals dissolve and melt, but these are frozen in time.
Figure 4: Twin, the repetitive form of nature is one of it’s greatest assets.
Figure 2
Figure 3
Figure 4
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