A hundred years ago, on May 8, 1915, the first piece
of opal was found in Australia. Willie Hutchinson was prospecting for gold with
his father in a desert town called Coober Pedy when he found a few pieces of
whitish iridescent rainbow-coloured stones. Coober Pedy is now the “opal
capital of the world.” It produces 80% of the world’s opals (BBC, May 8, 2015).
A group of international geologists hope to legally
define the opal, Australia’s national gemstone, as a Global Heritage Stone
Resource (GHSR) in order to recognize and preserve the opal’s significance in
human culture. No stone has yet been designated a GHSR status.
Initially the geologists wanted to recognize specific
construction rocks, such as Portland stone, Carrara marble, Sydney sandstone,
and Norwegian larvikite. They want to designate and protect particular stones
and rocks for conservation. But when the opal was added to the list, it was a
controversial decision, even amongst geologists. Some stated that opal was not
a construction stone because it was processed as jewellery.
The centenary of opals aims to highlight the
magnificence of their geological context. They result from the Eromanga Sea
that covered central Australia about 100 million years ago – it was the great
central sea. Opals in Coober Pedy are derived from sedimentary effects. Acidic
fluids dissolved silica from sandstone rich in quartz, which gives the stone
iridescence – a rainbow effect. Opals found in other locations originate from
volcanic events, not sedimentary settings.
The Global Heritage Stone Resource project commenced
in 2008. The project has not yet designated its first status to any stone – but
the honour is likely to go to Portland stone, the cream coloured building
limestone found in quarries in Dorset on the south coast of England. St. Paul’s
Cathedral and Buckingham Palace in London are constructed from Portland stone,
and so is the United Nations building in New York. So the opal, a controversial
choice, may take another hundred years before it makes the GHSR status as a
heritage stone.
MARTINA NICOLLS is an international
aid and development consultant, and the author of:- The Shortness of
Life: A Mongolian Lament (2015), Liberia’s Deadest Ends (2012), Bardot’s Comet
(2011), Kashmir on a Knife-Edge (2010) and The Sudan Curse (2009).
Comments
Post a Comment