Wopmayite

Chemical formula: Ca₆Na₃&#₉₇₄₄;Mn₂+(PO₄)₃(PO₃OH)₄

Wopmayite is a rare calcium, sodium, and manganese phosphate, forming colorless to pale pink, tabular crystals.

## Characteristics Wopmayite is a complex, hydrated phosphate belonging to the alluaudite group. It occurs as small, tabular or bladed crystals, usually not exceeding 1 mm in length. Crystals are most often gathered in radial or randomly oriented aggregates. It is a transparent mineral with a vitreous luster. ## Physical Properties Wopmayite crystals exhibit a hardness of approximately 5 on the Mohs scale. They are brittle and have an uneven fracture. The mineral's density is about 3.03 g/cm³. ## Colors and Varieties Wopmayite is typically colorless, sometimes taking on pale pink or pale yellow hues. No varieties have been distinguished. ## History and Name The mineral was discovered in the Tanco pegmatite deposit in Bernic Lake, Manitoba (Canada). Its name, approved by the IMA in 2004, comes from the Wopmay Orogen, a large orogenic belt in northwestern Canada. This honors Canadian geologist Paul F. Hoffman, who conducted research in this area. Type material is preserved in the collections of the Canadian Museum of Nature in Ottawa. ## Applications Due to its rarity and small crystal size, wopmayite has no industrial application and is solely an object of interest for collectors specializing in rare minerals and scientists.

Properties

Mohs hardness: 5
Luster: Vitreous
Streak: White
Density: 3.03
Cleavage: Good on {010}
Fracture: Uneven
Transparency: Transparent
Crystal system: Monoclinic

Diagnostic features

## Identification Amateur identification of wopmayite is practically impossible. It requires advanced analytical methods such as X-ray diffraction (XRD) and chemical spectroscopy (EDS/WDS). It can be initially suspected based on its characteristic paragenesis in the Tanco pegmatite. ## Distinguishing from Similar Minerals Wopmayite can be confused with other colorless or pale pink phosphates found in pegmatites, such as strengite, phosphosiderite, or other minerals from the alluaudite group. Definitive distinction is only possible through laboratory analysis. ## Crystal Forms It forms flattened, tabular or bladed crystals with a hexagonal outline, elongated along the crystallographic axis. Crystals often form radial aggregates or irregular clusters.

Geological environment

## Genesis Wopmayite is a hydrothermal mineral, crystallizing in the late stage of the evolution of complex lithium- and phosphorus-rich granitic pegmatites. It forms in alteration zones where primary phosphates undergo transformations under the influence of hydrothermal solutions. ## Mineral Associations In its type locality (Tanco pegmatite), it co-occurs with minerals such as quartz, albite, eucryptite, strengite, phosphosiderite, tancoite, whitlockite, and other complex phosphates. ## Localities The only confirmed occurrence of wopmayite in the world is the Tanco pegmatite, located at Bernic Lake in Manitoba, Canada.

Rarity

Extremely rare

For collectors

## Quality Criteria For collectors, the most important aspect is the presence of well-formed, even microscopic, wopmayite crystals, ideally forming aesthetic aggregates. Specimens where wopmayite contrasts with associated minerals are highly valued. The clarity and transparency of the crystals also increase the specimen's value. ## Popular Localities All collector specimens come from a single location – the Tanco mine in Canada. This is the only known locality for this mineral, making each specimen unique.

Care and storage

## Cleaning Utmost caution is recommended. It is safest to use compressed air to remove dust. If wet cleaning is necessary, use distilled water and a very soft brush, avoiding strong rubbing. The specimen should be thoroughly dried immediately. ## What to Avoid Absolutely avoid all acids and strong chemicals, which can damage the mineral. Wopmayite is brittle, so it should be protected from impacts and vibrations. It should not be cleaned with ultrasonics. ## Storage Wopmayite specimens, due to their small size and fragility, should be stored in sealed, padded "micromount" boxes to protect them from mechanical damage and dust.

Sources

IMA Mineral List (CNMNC)