The Earth's 2550 rarest minerals, including several beauties from Victoria, have been catalogued – some with the potential to transform future manufacturing industry.
The colourful array of minerals, each sampled from five or fewer areas around the globe, are far rarer than pricey diamonds and precious gems.
They also reveal the diversity of near-surface environments. "Earth's rare minerals make our planet unique in the cosmos," said lead catalogue researcher Dr Robert Hazen, of the Carnegie Institution in Washington. The new catalogue has been accepted for publication in the journal American Mineralogist.
"The more we search and apply new techniques, and the better microscopes we employ to hunt for tiny crystals, the more new minerals we find," Dr Hazen explained.
About 120 new minerals are unearthed every year, roughly double that of two decades ago. "These increase the likelihood of finding novel crystal structures and advancing crystal chemistry," Dr Hazen said.
"They're also valuable in understanding Earth as a complex evolving system in which fluid-rock interactions and biological processes lead to new mineral-forming niches."
Earth is quite unique in the solar system, adds Professor Joel Brugger of Monash University. "There's lots of water around - on the surface but also at depth; many of our rare minerals form from water and contain this in as a key component," Professor Brugger said.
"There's lots of life - many organisms directly or indirectly contribute to the formation of minerals and mineral diversity; and our planet is geologically active, with volcanoes, plate tectonics, earthquakes and so on - and hence highly dynamic."
"Technology has caught up with the tiny size of most new minerals being described," said Dr Stuart Mills, the senior curator of geosciences at Museum Victoria.
"State-of-the-art equipment, such as Melbourne's synchrotron, has helped us describe new minerals that were impossible to characterise not long ago," Dr Mills explained.
At least a dozen rare minerals were discovered first in Victoria. "The state is home to quite a few rare minerals - including a few that are found only here," said Professor Brugger. "This is due to Victoria's complex geological history, resulting in many different types of rocks and ore deposits."
Victoria's first rare mineral was maldonite, from Nuggety reef in Maldon. Another, lakebogaite, was found by Dr Mills in the Lake Boga granite quarry near Swan Hill.
Technology has caught up with the tiny size of most new minerals being described.Dr Stuart Mills, Melbourne Museum
"The most interesting new mineral I've described is mössbauerite, which has industrial uses relating to water purification," Dr Mills said. "It is found along parts of the French coastline."
The Earth's surface is unique because of the oxygen and water on it – plus the geological activity underneath, he explained.
"Weathering of the rocks and minerals on the surface gives rise to thousands of secondary mineral species. Without water, most of these minerals would not exist."
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