To create buzz about an otherwise arcane subject, the University of Wisconsin-Madison showed off a tiny speck of zircon crystal believed to be the oldest known piece of Earth at about 4.4 billion years old.

Saturday's daylong celebration was to be capped with "The Rock Concert" by jazz musicians who composed music to try to answer the question: What does 4.4 billion years old sound like?

"This is it -- the oldest thing ever. One day only," said Joe Skulan, director of the UW-Madison Geology Museum, where the object was displayed under police guard. "The idea of having a big celebration of something that's so tiny -- we're playing with the obvious absurdity of it."

Jazz Passengers, a six-piece group from New York, was hired to compose music for the event. Composer Roy Nathanson said he mixed humor, jazz music, computer-generated beats and the occasional rocks being banged together to "follow the geological history of how this zircon came about."

Measuring little more than two human hairs in diameter, the tiny grain of zircon crystal was found in the Jack Hills region of Australia and is estimated at 4.4 billion years old. It was dated by Simon Wilde, a professor in the School of Applied Geology at Curtin University of Technology in Perth, Western Australia. Wilde will deliver a free public lecture on the geology and zirconology of the Jack Hills region of Australia at 3:30 p.m. on Friday, April 8, in AB20 Weeks Hall, 1215 W. Dayton St.

A 2001 analysis of Wilde's zircon by geochemist John Valley provided evidence that the early Earth was much cooler than previously believed, and that water and oceans, key preconditions for life, formed much earlier than scientists had previously imagined. Subsequent analysis by graduate student Aaron Cavosie has supported these conclusions.

Valley's analysis of the Jack Hills zircon was conducted, in part, with the aid of a device known as an ion microprobe, a machine capable of extracting chemical and isotope ratios from very small samples. In the case of the Jack Hills zircon crystal, Valley's work showed that the mineral could only have formed as the result of a low temperature environment on Earth's surface.

At the time, Valley and his students needed to travel to Scotland to use one of the few ion microprobes available. UW-Madison now is installing its own ion microprobe, and the $3 million device will be available for public viewing concurrent with the zircon display...