Behoite

Chemical formula: Be(OH)<sub>2</sub>

A rare beryllium hydroxide, forming tiny, white or colorless crystals in pegmatites and nepheline syenites.

## Characteristics Béhoite is a beryllium hydroxide, a polymorph of clinobéhoite. It occurs as very small, usually microscopic crystals with a pseudo-octahedral or tabular habit. It forms granular aggregates, rosette-like clusters, as well as coatings and crusts on other minerals. It is typically colorless, white, or grayish, exhibiting a vitreous luster, and also a pearly luster on cleavage surfaces. ## Physical Properties It is a soft and very light mineral, with a density of approximately 1.90-1.92 g/cm³. It is transparent to translucent. It possesses perfect cleavage in one direction, which makes it brittle and susceptible to mechanical damage. ## Colors and Varieties This mineral does not form colored varieties. Its coloration is limited to shades of white, gray, or it is completely colorless. It has no named commercial or gemological varieties. ## History and Name Béhoite was first described in 1962. Its name directly refers to its chemical composition – the elements Beryllium (Be) and the hydroxide group (OH). ## Uses Due to its rarity and occurrence as small crystals, béhoite has no industrial applications. It is of purely scientific and collector's interest, being an object of interest for specialized collectors of rare minerals.

Properties

Luster
Vitreous, Pearly
Streak
White
Density
1.90-1.92
Cleavage
Perfect on {001}
Transparency
Transparent to translucent
Crystal system
Orthorhombic

Diagnostic features

## Identification Identifying béhoite in the field is very difficult. Key indicators include its occurrence environment (alteration zones in alkaline pegmatites), co-occurrence with other beryllium minerals, and the characteristic pseudo-octahedral habit of very small, white crystals. Definitive identification requires advanced analytical methods, such as X-ray diffraction (XRD). ## Distinguishing from similar minerals Béhoite is visually indistinguishable from its monoclinic polymorph – clinobéhoite. It can also be confused with other fine-grained, white secondary minerals, such as some zeolites (e.g., natrolite) or carbonates. Differentiation is based on crystal shape analysis (if visible) and chemical tests. ## Crystal forms Crystals are most often pseudo-octahedral or thick tabular. They usually form radial or rosette-like aggregates, as well as fine-grained coatings and crusts.

Geological environment

## Genesis Béhoite is a secondary mineral, formed under low-temperature hydrothermal alteration conditions. It forms as a result of the alteration of primary beryllium minerals, such as beryl, chkalovite, or epididymite, within alkaline pegmatites and nepheline syenites. ## Mineral associations It most commonly co-occurs with minerals such as albite, natrolite, analcime, chkalovite, epididymite, genthelvite, hambergite, and other rare beryllium minerals. ## Localities The most important localities of this mineral worldwide include its type locality – the Ermakovskoe beryllium deposit in Siberia (Russia), the Ilímaussaq alkaline complex in Greenland, the Khibiny and Lovozero massifs on the Kola Peninsula (Russia), and the famous Mont Saint-Hilaire locality in Quebec (Canada).

Rarity

Rare

For collectors

## Quality criteria The quality of béhoite specimens, which are almost always micromounts, is assessed based on several criteria. The sharpness and development of pseudo-octahedral crystals are most important. Specimens with distinct, lustrous crystals forming aesthetic rosettes or freely grown on the matrix are highly valued. Association with other rare or colorfully contrasting minerals is also important. ## Popular localities Mont Saint-Hilaire in Canada and the alkaline massifs on the Kola Peninsula in Russia are considered sources of the best quality collector specimens. Specimens from these localities are characterized by relatively good crystal development.

Care and storage

## Cleaning Specimens should be cleaned only mechanically, using a soft brush. If necessary, distilled water can be used. Ultrasonic cleaners should be avoided, as they can damage delicate crystals. ## What to avoid The mineral is sensitive to shocks and impacts due to its perfect cleavage. Contact with acids and other strong chemicals should be avoided. As a secondary mineral, it may be unstable in fluctuating humidity conditions. ## Storage The safest form of storage, due to the small size and fragility of the crystals, is a "micromount" box. It protects the specimen from mechanical damage and dust, while allowing for observation under a microscope.

Sources

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