Alpha-D lactose monohydrate

Chemical formula: C<sub>12</sub>H<sub>24</sub>O<sub>12</sub>

Alpha-D-lactose monohydrate is a crystalline form of milk sugar, an organic compound, not a mineral in the geological sense.

## Characteristics Alpha-D-lactose monohydrate is an organic compound, a disaccharide found in mammalian milk. It is not classified as a mineral by the International Mineralogical Association (IMA) because it does not form through geological processes. This entry describes the properties of its synthetically or laboratory-produced crystals. It crystallizes in the form of colorless or white, well-formed crystals, which can reach significant sizes under controlled conditions. ## Physical Properties The crystals are relatively soft and brittle. They have a vitreous luster and are transparent to translucent. The density is approximately 1.54 g/cm³. This compound is highly soluble in water, which is its key physicochemical property. ## Colors and Varieties This compound is typically colorless or white. It does not form colored varieties or commercial varieties in the mineralogical sense. Its appearance primarily depends on purity and crystallization conditions. ## History and Name The name "lactose" comes from the Latin word *lac* (milk) and the suffix *-ose*, which is a standard ending for sugar names. It was discovered in milk in 1619 by the Italian physician Fabrizio Bartoletti and identified as a sugar in 1780 by Carl Wilhelm Scheele. ## Applications Lactose monohydrate is widely used in the food industry as an ingredient in many products, including infant formulas. In the pharmaceutical industry, it is one of the most commonly used excipients, serving as a filler and binder in tablets and capsules.

Properties

Luster
Vitreous
Streak
White
Density
1.54
Cleavage
Perfect on {010}
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification A key diagnostic feature is its complete and relatively rapid solubility in water. Other helpful identification features include low hardness, lightness (low density), vitreous luster, and a sweet taste (although taste testing is not a recommended identification method in mineralogy). ## Distinguishing from Similar Minerals It is distinguished from quartz by its extremely low hardness and water solubility. It is distinguished from halite (rock salt) by its sweet taste (halite is salty), different crystal habit (halite crystallizes in the isometric system), and lack of a salty odor. It differs from sucrose (table sugar) in its crystalline form – sucrose crystals are also monoclinic, but usually have a different habit (thicker, more blocky). ## Crystal Forms It crystallizes in the monoclinic system, forming tabular or prismatic crystals. In scientific literature, their characteristic shape, resulting from the uneven development of individual faces, is often described as a "tomahawk."

Geological environment

## Genesis Alpha-D-lactose monohydrate is not a mineral and does not form through geological processes. It is an organic compound crystallized from supersaturated aqueous solutions, mainly under industrial or laboratory conditions. The main source of lactose is whey, a byproduct of cheese production. ## Mineral Associations Not applicable, as it does not occur in geological environments and does not form parageneses with minerals. ## Localities Not applicable. It is a substance produced industrially worldwide, not mined or found in specific geological sites.

Rarity

Extremely rare

For collectors

## Quality Criteria Lactose monohydrate is not a mineral in the collector's sense. Any specimens are exclusively laboratory or industrially grown crystals. Their attractiveness is assessed based on size, purity (transparency), and geometric perfection of form, not according to criteria used for natural minerals. ## Market Prices Not applicable. It is an inexpensive, widely available chemical and pharmaceutical raw material. ## Popular Localities Not applicable.

Care and storage

## Cleaning Crystals are water-soluble, so they must not be wet cleaned. Dust can only be removed with a soft brush or a gentle stream of compressed air from a safe distance. ## What to Avoid Contact with water and other solvents, as well as high humidity, must be strictly avoided. Crystals are sensitive to high temperatures – they melt at approximately 202°C, simultaneously decomposing. They should be protected from direct sunlight. ## Storage Specimens should be stored in a dry place, preferably in a tightly sealed container, display case, or cabinet, to protect them from moisture and contamination.

Sources

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