Weinebeneite

Chemical formula: CaBe₃(PO₄)₂(OH)₂·4H₂O

Weinebeneite is a very rare hydrated calcium beryllium phosphate, forming colorless, prismatic crystals with a vitreous luster.

## Characteristics Weinebeneite is an exceptionally rare mineral from the phosphate group. It occurs as elongated, prismatic crystals that can reach up to 2 cm in length, although they are usually much smaller. The crystals are most often colorless and transparent, exhibiting a strong vitreous luster on their faces. They typically form small, loose aggregates or grow on other minerals in rock cavities. ## Physical Properties This mineral is characterized by a hardness of approximately 3 on the Mohs scale, making it relatively soft. Its density is low, around 2.23 g/cm³. The crystals exhibit perfect cleavage in one direction, which is visible when attempting to separate them. The luster is distinctly vitreous, and the mineral is transparent. ## Colors and Varieties Weinebeneite is usually colorless. No colored varieties or trade names have been reported, which is typical for such rare minerals of purely scientific and collecting interest. ## History and Name The mineral's name comes from its discovery locality – the Weinebene Pass in the Koralpe mountain range, on the border of Carinthia and Styria in Austria. It was first described in 1991 by Austrian mineralogists Josef Taucher and Walter Postl, and approved by the International Mineralogical Association (IMA) in the same year. ## Uses Due to its extreme rarity, weinebeneite has no industrial applications. It is solely an object of interest for specialized collectors of rare minerals and scientists studying the mineralogy of pegmatites.

Properties

Mohs hardness
3-4
Color
Colourless
Luster
Vitreous
Streak
White
Density
2.15
Cleavage
Perfect on {010}
Fracture
Irregular/Uneven,Splintery
Transparency
Transparent,Translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Weinebeneite can be identified by its characteristic, elongated and prismatic crystals with a cross-section close to square. Key features include its colorlessness, strong vitreous luster, low hardness, and occurrence in a specific geological environment – lithium pegmatites. Perfect cleavage is also an important indicator. ## Distinguishing from Similar Minerals It can be confused with other colorless pegmatite minerals, such as quartz, beryl (goshenite), or some zeolites. It is distinguished from quartz and beryl by its significantly lower hardness (approximately 3, compared to 7-8). From zeolites, it can be distinguished based on crystal form and specific mineral associations. Final confirmation requires advanced analytical methods (e.g., XRD, EDS). ## Crystal Forms Crystals are prismatic, elongated along one axis, often terminated by simple faces. They usually occur as single, well-formed columns or in small, radial or haphazard aggregates.

Geological environment

## Genesis Weinebeneite is a hydrothermal mineral, crystallizing in the late stage of the evolution of complex granitic pegmatites, rich in lithium and phosphorus. It forms in vugs and rock fissures, often in association with other rare phosphate minerals. ## Mineral Associations This mineral co-occurs with other phosphates, such as wardite, eosphorite, zircon, apatite, as well as quartz, albite, and muscovite. In its type locality, it was found in association with rare beryllium phosphates, indicating the unique chemical conditions present during its crystallization. ## Localities The only confirmed and well-documented occurrence of weinebeneite in the world is its type locality: the pegmatite quarry at Weinebene Pass in the Koralpe range, Austria. This locality is known for the occurrence of many rare phosphate minerals.

Rarity

Extremely rare

For collectors

## Quality Criteria The most prized weinebeneite specimens are those with sharply terminated, transparent, and lustrous crystals, ideally set on a contrasting rock matrix. Due to its rarity, even small microcrystals are considered valuable. Crystal size, transparency, and lack of mechanical damage are the main factors influencing collectible value. ## Popular Localities The only source of collector specimens is the type locality in Austria. Material from this location is extremely difficult to acquire and appears on the market very sporadically, usually within a closed circuit among specialized collectors.

Care and storage

## Cleaning Weinebeneite specimens should be cleaned with the utmost care. It is recommended to use only compressed air to remove dust. If wet cleaning is necessary, use distilled water and a very soft brush, avoiding any pressure due to the mineral's low hardness and perfect cleavage. ## What to Avoid Ultrasonic cleaners, which can destroy the crystals, must be absolutely avoided. The mineral is sensitive to acids and other chemicals. It should not be heated or exposed to prolonged strong sunlight, although there is no evidence of it fading. ## Storage Specimens should be stored in separate, padded collector boxes to prevent scratches and mechanical damage. Due to its fragility, it is not suitable for display in places where it might be exposed to vibrations or touch.

External references

Sources

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