Physical and chemical properties
Pure white, can be dyed into other colors due to impurities. The aggregate is dull or waxy. It has extremely complete cleavage, hardness 2.0~3.5, relative density 2.60~2.63. The dense block has a rough feel, absorbs water when dry, and has a plasticity in the wet state, but does not swell when added.
Under the polarizer: colorless. Fine scales. Biaxial crystal (-). 2V = 10~57°. Np=1.560~1.570, Nm=1.559~1.569, Np=1.533~1.565.
Kaolinite is widely distributed, mainly due to the change of aluminosilicate in the acidic medium, weathering or low temperature hydrothermal replacement.
Under the action of low temperature hydrothermal fluid, when the acidic aqueous solution containing CO2 acts on the alkali-free aluminosilicate and silicate, it can cause kaolinite, and the kaolinite formed is often feldspar, mica, topaz, etc. An illusion.
Identification feature
The dense soil-like block is easily crushed into powder, sticky tongue, and plasticity added to the water, and loses moisture after heating in a sealed test tube. After burning, it reacts blue with cobalt nitrate (Al). Kaolinite and its polytypes can be distinguished by X-ray diffraction and thermal analysis. The difference between halloysite and kaolinite is that there is a significant endothermic effect in the range of 100-200 °C, which is equivalent to the removal of interlayer water.
Full Bed Set,White Bedding Sets,Cheap Bedding Sets,Solid Flat Sheet
changxing sanxing textile co.,ltd , https://www.sxhometextile.com