Also found in: Dictionary, Wikipedia.
Related to Halloysite: Nontronite, beidellite


Al2Si2O5(OH)4·2H2O Porcelainlike clay mineral whose composition is like that of kaolinite but contains more water and is structurally distinct; varieties are known as metahalloysites.



(named for the Belgian geologist J. B. Omalius d’Halloy, 1783-1875), a claylike mineral of the group of layered silicates having the chemical composition Al4[Si4O10](OH)8·4H2O. It is close in composition to kaolinite, from which it is distinguished by a higher water content. Halloysite crystallizes in a monoclinic system. It is found in the form of claylike crypto-crystalline aggregates. The coloration is usually white but can sometimes be from yellowish to brown (from iron oxides), with a dull luster. Its hardness on the mineralogical scale is one to two; its density is 2,000 to 2,200 kg/m3. Halloysite is a typical product of the weathering of the aluminum silicates of igneous rocks, especially feldspars. It is common, but large accumulations are unusual.

References in periodicals archive ?
Applied Minerals will exclusively supply halloysite clay to BASF for the development and sale of co-branded halloysite clay-based products to key BASF markets, including paints and coatings, inks, rubber, adhesives, paper and ceramic honeycomb catalytic substrates.
Halloysite (location Biela Hora, Michalovce, Slovakia) was ground into powder using a laboratory ball mill.
According to the company, the increase in revenues in 2016 was driven by a increase in sales of AMIRON iron oxide and DRAGONITE halloysite clay.
In some soils under a drier climate, and where there is high soluble Si, halloysite forms preferentially in place of allophane and imogolite (Shoji et al.
Halloysite, a 1:1 clay mineral chemically similar to kaolinite except in its higher hydrated water content shows tubular morphology but also spherical, platy and semi rolled forms.
Effects of unfolded and intercalated halloysites on mechanical properties of halloysite-epoxy nanocomposites," Composites A: Applied Science and Manufacturing, vol.
A special category of sub-micron particles is naturally occurring halloysite nanotubes (HNTs) derived from the clays of Utah.
Introduction of the halloysite nanotube coating has been described (22).
OTC BB: AMNL), a producer of halloysite clay from its wholly owned Dragon Mine property in Utah, has received USD10m through the sale of 10 million units to Samlyn Capital LLC.
It could be concluded that, out of the seventeen villages, six (6) of them had the mineral Vermiculite, three (3) had Montmorillonite, two (2) each had Halloysite and Mica respectively; and the last four (4) could not be classified because their values were above the standard Chart for the various mineral types.
Finally, certain minerals found predominantly in altered areas, including halloysite, siderite and alunite, [3, 17], have been used to identify subsurface reservoirs.
The first class included all used samples of clay minerals (biotite, muscovite, illite, chlorite, kaolinite, dickite, halloysite, montmorillonite, notronite, hectorite and vermiculite).