Alum Stone: What You Should Know About This “Natural” Compound

Mineral alum is a translucent crystal that has been used since ancient times for its astringent, antiseptic, and deodorizing properties. It has become popular as a "natural" alternative to commercial deodorants, but it is important to understand what this mineral really is, how it is obtained, and what its use implies.

What is mineral alum?

Alum is a double salt of aluminum and potassium, whose chemical name is potassium aluminum sulfate (KAl(SO₄)₂·12H₂O). There are also variants with sodium or ammonium, but the most common in personal products is potassium alum.

Mineralogically, alum belongs to the group of hydrated sulfates. Its natural crystalline form is found in deposits of volcanic origin or in areas with strong hydrothermal activity, where hot water carries sulfate-rich minerals and crystallizes them over time.

Where is alum found and how is it extracted?

Alum is found in natural deposits (mines) in regions such as:

• Syria
• Morocco
• China
• Brazil
• Italy

Currently, many companies extract alum through surface mining, crushing the rocks containing the mineral and purifying it to obtain the commercial crystal. Subsequently, it is recrystallized and presented in the form of polished "alum stone" or powder for cosmetic use.

Does alum crystal contain aluminum?

Yes. All alum contains aluminum. Although it sounds milder because it has names like "potassium alum" or "mineral alum," the truth is that it is a form of aluminum that is soluble in water. This means that it can penetrate the skin, especially when applied to damp, freshly shaved skin or skin with micro-lesions.

Although it is promoted as a safer alternative, alum contains aluminum, which is a metalloestrogen, meaning it can mimic the action of estrogens in the body. This has raised concerns about its possible relationship with hormonal imbalances and diseases such as breast cancer.

Maxalli: no aluminum, no risks

At Maxalli, we decided to completely eliminate any form of aluminum from our deodorants. We believe that what is natural should be safe, honest, and functional. We use ingredients such as:

• Citric Acid Ester, to balance pH without harming the skin

• Antimicrobial essential oils that fight bad odor without blocking sweat

• Candelilla wax, for a firm and vegan texture

Alum may be natural, but that doesn't make it harmless.
Maxalli offers a real alternative: no aluminum, no deception, no risks.