Clay minerals

Clay minerals are hydrous aluminium phyllosilicates, sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces.

Clay minerals form in the presence of water and have been important to life, and many theories of abiogenesis involve them. They have been useful to humans since ancient times in agriculture and manufacturing.

Properties

Clays form flat hexagonal sheets similar to the micas. Clay minerals are common weathering products (including weathering of feldspar) and low-temperature hydrothermal alteration products. Clay minerals are very common in fine-grained sedimentary rocks such as shale, mudstone, and siltstone and in fine-grained metamorphic slate and phyllite.

Clay minerals are usually (but not necessarily) ultrafine-grained (normally considered to be less than 2 micrometres in size on standard particle size classifications) and so may require special analytical techniques for their identification and study. These include x-ray diffraction, electron diffraction methods, various spectroscopic methods such as Mössbauer spectroscopy, infrared spectroscopy, Raman spectroscopy, and SEM-EDS or automated mineralogy processes. These methods can be augmented by polarized light microscopy, a traditional technique establishing fundamental occurrences or petrologic relationships.

Clay

Clay is a fine-grained natural rock or soil material that combines one or more clay minerals with traces of metal oxides and organic matter. Clays are plastic due to their water content and become hard, brittle and non–plastic upon drying or firing. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure. Depending on the content of the soil, clay can appear in various colours, from white to dull gray or brown to a deep orange-red.

Clays are distinguished from other fine-grained soils by differences in size and mineralogy. Silts, which are fine-grained soils that do not include clay minerals, tend to have larger particle sizes than clays. There is, however, some overlap in particle size and other physical properties, and many naturally occurring deposits include both silts and clay. The distinction between silt and clay varies by discipline. Geologists and soil scientists usually consider the separation to occur at a particle size of 2 µm (clays being finer than silts), sedimentologists often use 4–5 μm, and colloid chemists use 1 μm.Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 μm and silt particles as being larger.

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Latest News for: clay mineral

Eels shock Miners

Vincennes Sun-Commercial 25 Feb 2025
The Linton Miners hosted a conference game against the Clay City Eels Tuesday night. The Eels stunned Miner nation, defeating Linton 63-54 to win the conference championship ... .

Radioactive roads? EPA gives Mosaic Co. green light on phosphogypsum road study

Herald-Tribune Sarasota 24 Feb 2025
The study has already garnered support from the Florida Department of Transportation and Gov ... The Mosaic Co ... Spokeswoman Ashleigh Gallant said ... INFOGRAPHIC ... After the mineral is scooped from underground, the rock is separated from sand and clay ... Sources.

Greene County property transfers

Observer-Reporter 23 Feb 2025
The following property transfers have been recorded in the Greene County Recorder of Deeds office ... Kerri L ... Brian Clay Burgess, et ux., to Christopher V. Butler, Tracts, Oil, Gas, Coal, & Minerals, $3,500.00 (2-3-25) ... Windridge Minerals LLC to Robert A.

‘Technofossils’: how humanity’s eternal testament will be plastic bags, cheap clothes and chicken bones

The Observer 23 Feb 2025
“They’re going to be around in the strata for a long time and eventually you would expect little gardens of clay minerals growing in the space where the can was.

‘Technofossils’: how plastic bags and chicken bones will become our eternal legacy

AOL 22 Feb 2025
“They’re going to be around in the strata for a long time and eventually you would expect little gardens of clay minerals growing in the space where the can was.

Topgolf nears final approval in Canton, but potential wetlands impact in question

Detroit Free Press 20 Feb 2025
... more than 13 acres of wet-mesic flatwoods, a mixture of lowland and upland hardwoods in mineral soils that very frequently don't completely drain, often because of a clay layer below the surface.

Yukon Metals posts 2025 AZ Project exploration plans, Yukon Territory

Resource World 19 Feb 2025
Consistent copper mineralization was found along the prospected area ... Strongly clay-altered biotite-quartz diorite dykes were mapped in the vicinity of mineralization and are interpreted to be part of the Nutzotin suite of intrusions.

What We Know About “The Face On Mars” First Seen In 1976

IFL Science 08 Feb 2025
The mesas in Cydonia are said to be rich in ice, and a recent study of mesas in the Chryse Planitia region showed that they contain clay minerals, which only form when water interacts with rock for a very long time.

Zion Health Releases Five Newly Reformulated ClayBrite Toothpastes with Calcium Hydroxyapatite

GetNews 05 Feb 2025
... Minerals ... The mixture provides better cleansing, neutralizes acidity, absorbs pollutants, and prevents plaque accumulation when combined with ionic clay minerals, especially calcium bentonite clay.

Africa needs mineral security, too

B & FT Online 05 Feb 2025
At the top of their agenda is the Africa’s reserves of critical minerals and how the continent can capitalize on their role in the global economy ... to whose economy the minerals are important and whose supply chains are at risk.

Best California hot and mineral springs spas and resorts for cool vacations

Desert Sun 05 Feb 2025
Soak up more than just sunshine in California at natural mineral and hot springs, bubbling up throughout the state ... The resort's Club Mud offers various treatments combining spring mineral water with local red clay mud.

Critical minerals: Goals and gaps

Deccan Herald 05 Feb 2025
... investment in 2023 alone.</p>.<p>Second, India lacks advanced capabilities in extracting and processing minerals like lithium from clay deposits or recovering rare earths from e-waste.
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