Sepiolite

SepioliteIt is a fibrous, hydrated magnesium silicate, typically appearing in colors such as white, light gray, and light yellow, opaque and lacking luster. Some of them resemble clumps of soil, while others take on strange crust-like or nodular forms. Under an electron microscope, they can be seen as filaments gathered together in sheet-like arrangements. Sepiolite has a peculiar characteristic: when it comes into contact with water, it absorbs a large amount of water and becomes soft, but once it dries, it hardens again.

Physical properties of sepiolite：

It belongs to the orthorhombic or monoclinic crystal system; its color is variable, generally appearing pale white or grayish-white; it has a silky luster, sometimes a waxy luster; its streak is white, opaque, with a smooth texture that feels sticky to the tongue; its Mohs hardness ranges between 2 and 2.5; it is light in weight, with a density of 1 to 2.2 g/cm³; it has low shrinkage and good plasticity.
Chemical composition of sepiolite:

The elements are silicon (Si) and magnesium (Mg).

Its standard crystal chemical formula is Mg₈(H₂O)₄[Si₆O₁₆]₂(OH)₄·8H₂O.

The SiO2 content is generally between 54% and 60%, while the MgO content is mostly in the range of 21% to 25%.