Synthetic and Natural Deodorant Crystals Compared

Once an all-natural market, crystal deodorants are now being overshadowed by their synthetic counterpart, and the market is saturated with powerful brands marketing synthetic products with 'natural' labels.  30 years ago the crystal deodorant market was untouched and just beginning to evolve. Consumers most likely did not even know what natural deodorant was, let alone crystal deodorant. But now that demand for crystal deodorant has drastically increased  manufacturers have found cheaper ways to produce crystal deodorants, and the cheapest and most commonly used raw material is synthetic potassium alum.

There are two types of raw materials used for producing deodorant crystals: natural potassium alum crystal, which is an entirely natural occurring mineral salt, and synthetic potassium alum crystal, which is chemically manufactured.

Natural potassium alum crystal is translucent crystalline mineral rock that contains veins.  It is odorless, chemical free, alcohol free, hypoallergenic, non-sticky, non-staining, and non-irritating.  It is routinely extracted throughout the world, especially around the Mediterranean and Andes in South America.

Synthetic alum is chemically synthesized by mixing aluminum hydroxide (ATH) with potassium or ammonium sulfate in acid.  After additional chemical reactions and mixtures, the final product is either synthetic potassium alum or ammonium alum powder.  The alum powder is then pressed to form deodorant stones or crystals, which appear as a white, opaque, solid stone.  When the synthetic deodorant stone is rubbed onto the body a small trace of aluminum hydroxide is also placed on the skin. 

However, beyond the obvious difference of one stone being natural, and one being synthetic, there is also a visual difference.  The presence of aluminum hydroxide (ATH), a cosmetic opacifying agent, in the manufacturing process of the synthetic deodorant crystal results in the crystal appearing completely opaque, whereas the natural deodorant crystal is translucent. The difference is clearly visible below with a side-by-side comparison of synthetic alum crystal and natural potassium alum crystal: