Moqui Marbles, hematite concretions, from the Navajo Sandstone of southeast Utah.
Scale cube, with "W", is one centimeter square.
UNL discovery has implications for finding life on Earth, Mars PhysOrg - August 16, 2012
Moqui marbles, unusual balls of rock that can be found rolling around the southwestern U.S. sandstone regions, were formed roughly 2 million years ago with the help of microorganisms. This discovery by a University of Nebraska-Lincoln research team has implications for finding life on Mars and for better understanding Earth's past. Moqui marbles, which range in size from BBs to cannonballs, weather out of sandstone and have a hard, round shell made of iron oxide, or rust, and a soft, sandy interior. Previous theories of their formation had suggested a chemical reaction devoid of life, but Weber's team discovered clear evidence that microorganisms played a role.
To determine that microorganisms were involved, researchers looked for telltale signs of life, principally nitrogen and organic carbon. Compared to minerals, living beings usually contain a "lighter" isotope of carbon, or one with fewer neutrons, and chemical analyses indicated the presence of this lighter carbon. Looking at the material using a field emission scanning electron microscope, they discovered structures that resembled microorganisms. Nanoscale geochemical analyses conducted by colleagues at the University of Western Australia provided a detailed chemical composition of the structures that further indicate microbial life.
From Wikipedia - Navajo Sandstone
The Navajo Sandstone is also well known among rockhounds for its hundreds of thousands of iron oxide concretions. They are believed to represent an extension of Hopi Native American traditions regarding ancestor worship ("moqui" translates to "the dead" in the Hopi language). Informally, they are called "Moqui marbles" after the local proposed Moqui native American tribe. Thousands of these concretions weather out of outcrops of the Navajo Sandstone within south-central and southeastern Utah within an area extending from Zion National Park eastward to Arches and Canyonland national parks. They are quite abundant within Grand Staircase-Escalante National Monument.
The iron oxide concretions found in the Navajo Sandstone exhibit a wide variety of sizes and shapes. Their shape ranges from spheres to discs; buttons; spiked balls; cylindrical hollow pipe-like forms; and other odd shapes. Although many of these concretions are fused together like soap bubbles, many more also occur as isolated concretions, which range in diameter from the size of peas to baseballs. The surface of these spherical concretions can range from being very rough to quite smooth. Some of the concretions are grooved spheres with ridges around their circumference.
The abundant concretions found in the Navajo Sandstone consist of sandstone cemented together by hematite (Fe2O3), and goethite (FeOOH). The iron forming these concretions came from the breakdown of iron-bearing silicate minerals by weathering to form iron oxide coatings on other grains. During later diagenesis of the Navajo Sandstone while deeply buried, reducing fluids, likely hydrocarbons, dissolved these coatings. When the reducing fluids containing dissolved iron mixed with oxidizing groundwater, they and the dissolved iron were oxidized. This caused the iron to precipitate out as hematite and goethite to form the innumerable concretions found in the Navajo Sandstone. These concretions are regarded as terrestrial analogues of the hematite spherules, called alternately Martian "blueberries" or more technically Martian spherules, which the Opportunity rover found at Meridiani Planum on Mars. Martian spherules have a blue hue in false-color images released by NASA in 2004.
Uploaded by 888Quetzalcoatl888 on Septenber 12, 2011
Video from Hole in the Rock Road outside of Escalante, Utah
From Ellie: The stones take me to the 2009 film Knowing when the hematite stones lifted as the 4 beings of light and the children left on the UFO to recreate once again.