Magnesium stearate

Chemical formula: Mg(C<sub>18</sub>H<sub>35</sub>O<sub>2</sub>)<sub>2</sub>

Magnesium stearate is a synthetic, organic magnesium salt of stearic acid, not a mineral.

Magnesium stearate is not a mineral in the geological sense, but a synthetically produced magnesium salt of stearic acid. It is an organic substance, not a naturally occurring inorganic compound formed by geological processes, which is a fundamental criterion for the definition of a mineral. For this reason, it is not classified as a mineral species by the International Mineralogical Association (IMA), does not occur in nature in the form of deposits or crystals, and is not of interest in mineralogy or mineral collecting. It is a white, very light powder, feeling greasy or soapy to the touch. It is insoluble in water. Due to its physical properties, mainly as a lubricant and anti-adhesion agent, it is widely used in the pharmaceutical industry (as an excipient in tablets), food industry (as food additive E470b), and in the production of cosmetics and plastics. Therefore, filling in standard encyclopedic sections for a mineral is impossible and substantively unjustified.

Properties

Mohs hardness
~1.5
Luster
Pearly
Streak
White
Density
1.026
Cleavage
Perfect
Transparency
Translucent
Crystal system
Monoclinic

Diagnostic features

## Identification It is a very light, fine, white powder, greasy and slippery to the touch. It does not form natural crystals or aggregates in the mineralogical sense. ## Distinguishing from similar substances It can be confused with other white, powdered substances, such as talc or starch. It is distinguished by its characteristic, "soapy" or "greasy" slipperiness to the touch. ## Crystal forms As a synthetic product, it usually occurs as an amorphous powder or very fine, poorly formed platelets visible under high magnification. It does not form macroscopic crystals.

Geological environment

## Genesis It is not a mineral and does not form through geological processes. It is produced synthetically by the reaction of magnesium salts (e.g., magnesium sulfate) with salts of stearic acid (e.g., sodium stearate). ## Mineral associations Not applicable, as it does not occur in a geological environment. ## Localities Not applicable. It is an industrial product manufactured worldwide.

Rarity

Synthetic product

For collectors

Magnesium stearate is not of interest to mineral collectors, as it is a synthetic organic compound, not a naturally occurring mineral. It does not form aesthetic specimens, and its value is purely industrial.

Care and storage

## Cleaning As a synthetic product, it is not collected in specimen form requiring cleaning. ## What to avoid Avoid high temperatures, which can lead to melting (approx. 88°C) and decomposition. It is sensitive to strong acids. ## Storage Store in a tightly sealed container, in a dry place, away from heat sources and strong acids.

External references

Sources

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