At http://meetings.aps.org/Meeting/APR05/Event/29058 there is a short abstract by CJ Ransom and Wal Thornhill that claimed z-pinch simulations in the laboratory actually produced spherules (in an experiment). The idea was to reproduce a plasma discharge in order to create spherules, which duly happened, that were nearly identical in appearance to those found on Mars, the so called blueberries (Bulletin of the American Physical Society, the 2005 APS Spring Meeting).
The interesting thing is that spherules have also been found in terrestrial geological contexts – for instance, in the black mat layer at the Younger Dryas boundary event.
At www.thunderbolts.info/tpod/2005/arch05/050325blueberries.htm there is an expansion on the Martian phenomenon (with images). Plasma physicist uses electric arcs to replicate the mysterious spherules on the Red Planet. After spectroscopic analysis the blueberries were explained away as 'hematite concretions'. Hematite is an iron rich mineral and is the primary constituent in the soil surrounding the blueberries on Mars – but where did the hematite come from? Blueberries are, it seems, quite similar to hematite concretions in Texas and Moqui balls in Utah.
At www.thunderbolts.info/tpod/2007/arch07/071220stoneeggs.htm there is a Picture of the Day entitled, China's Stone Eggs. It is conjectured they too may have been created by high energy electrical arcs – discharging onto a hill. The Chinese eggs come in all sizes, from inches to feet in diameter – but were discovered during construction of a highway that cut through a hill (the stone eggs were inside). Stone spheres are common to other societies – the Olmec civilisation of Mexico for example where they are thought to have been carved by humans. In uniformitarianism spherules are formed by slow accumulation of minerals such as carbonate and water soluble compounds. Since many spherules are found in non sedimentary contexts, weathering before the elements, so the mystery grows – and mainstream geologists are not looking at electricity or solar flares playing a role.
At www.thunderbolts.info/tpod/2008/arch08/080418moeraki.htm the Picture of the Day is New Zealand's Moeraki Boulders – by far the most suprising of the three. Round nodules of solid stone were found on a beach in New Zealand – hundreds of them had fallen out of an eroding cliff face (another hill). They range in size from small to over 4m in diameter and geologist describe them as concretions. Is this definition wrong? In fact, what about other geological phenomena labelled as concretions – what is their origin?