Guide to using the Alum Stone

Alum Stone is actually a crystal extracted from a mineral called alunite or bauxite. At the time, the latter came from Syrian quarries but today it is present in mines, surface outcrops or volcanic soils all over the world. This mineral is a double sulfate of aluminum and potassium. In natural cosmetics, alum stone is used for different benefits. First of all for its astringent nature which means that it tightens the pores of the skin. This characteristic allows it to regulate perspiration and to be used as an antiperspirant and natural deodorant but it also reduces the deposition of sebum in oily skin. Thanks to this property, the stone also facilitates healing, it is often used following hair removal or shaving to stop micro-bleeding and soothe the skin.

You can find the Alum Stone in two forms:

• In block: Once purified, the potassium alum crystals are recrystallized in the form of a block or stick that can be used directly on the skin.

• In powder: The crystals are then ground into a very fine powder which will be incorporated into your homemade cosmetic preparations for the same properties.

Respectful of your skin and the environment, it is an ideal alternative to commercial deodorants. Without aluminum chlorohydrates, perfume, silicones, preservatives or propellant gases destroying the ozone layer, Alum Stone is your ally in natural cosmetics. Simple, quick to use and also advantageous from an economic point of view, the latter can be used for years without losing its effectiveness, knowing that a single 100 g stick is equivalent to the use of around ten conventional spray deodorants.

Aluminum is one of the most abundant natural elements in the earth's crust and which in very high doses in the bloodstream can be dangerous for human health. Recently, aluminum salts have been singled out for their increased presence in consumer products: water, food, medicines and cosmetic products. Like other chemical compounds, they would have an impact on the development of various neurological and cancerous pathologies.

Within cosmetic products, these are more precisely the aluminum chlorohydrates mostly found in commercial deodorants and antiperspirants which are blamed for their carcinogenic nature. They would facilitate the passage of aluminum into the body through the skin. However, no official study has determined whether or not aluminum passes through the skin. The National Agency for the Safety of Medicines and Health Products (formerly Afssaps) has assessed the risks to which cosmetic consumers are exposed when faced with different types of aluminum salts. This study did not demonstrate a link between aluminum and cancer but as a precaution, it was still decided to restrict the quantity of aluminum to 0,6 % in cosmetic products. It is also not recommended to use products containing aluminum on damaged skin in order to avoid any passage into the blood.

There Natural alum stone does not contain aluminum chlorohydrates and no official remark, study or fact has concluded that there is any toxicity on its part under reasonable conditions of use.

And yes, you have to be careful when you get alum stone because there is a natural one and another synthetic one. They differ in their manufacturing processes and chemical composition.
Stone natural is therefore alum potassium extracted from alunite which will be purified then recrystallized by natural methods over a period of approximately 6 months. The Alum Stone synthetic as for it is obtained by heavy polluting chemical processes. It is composed ofalum ammonium (N.H.₄)Al(SO₄)₂ from residues and ammonium salts, the majority of which comes from the nylon industry in Asia. The use of the latter has repeatedly reported irritation and inflammation in the armpits among consumers. So be careful and once again favor Mother Nature!

To make your natural alum stone stick, the extracted alunite will undergo four operations:

• there calcination : This step is carried out over one day and under very high temperature, between 600 and 700°C. It allows all the water to be lost from the ore in order to obtain anhydrous sulfate as well as alumina. It is very important to control the temperature during this stage because below 600°C the decomposition of the alunite is incomplete and above 700°C the sulfates are lost but they are necessary for the formation of the stone.

• there maceration : Then the anhydrous sulfate obtained is rehydrated during maceration by watering with water to form potassium alum of formula KAl(SO₄)₂•12H₂O. This stage is the longest and can last 2 to 4 months maximum until a pasty mass is obtained from which the alum potassium will be extracted.

• there leaching : This operation makes it possible to extract the potassium from alum following maceration. It consists of leaching the pasty mineral mass in hot or even boiling water in order to solubilize the alum and remove the impurities which are insoluble. This also aims to concentrate the alum potassium before its crystallization.

• there crystallization : This is the last step in making your stick. The hot solution of potassium alum previously recovered is placed in tanks in which it will cool over a fortnight to form crystals. Those placed in the center of the tanks are then recovered to be cut and polished according to the desired shape.