Pyrobelonite

Chemical formula: Pb₂+Mn₂+V₅+O₄(OH)

A rare lead and manganese vanadate, forming characteristic, acicular crystals of intense, reddish-orange color.

## Characteristics Pyrobelonite is a mineral from the vanadate group, chemically classified as a lead and manganese vanadate hydroxide. Its most characteristic feature is well-formed, prismatic or acicular crystals, which often form radial or divergent aggregates. The mineral's name refers to its "fiery" color and crystal habit. ## Physical Properties This mineral is relatively soft, with a hardness of about 3.5 on the Mohs scale. It is characterized by a high density, ranging from 5.46-5.50 g/cm³, which is typical for lead-bearing minerals. The luster is adamantine, sometimes transitioning to greasy. It is transparent to translucent. ## Colors and Varieties Pyrobelonite occurs in shades from bright red and reddish-orange to reddish-brown. Its color is one of the key diagnostic features. There are no commercial or color varieties distinguished. ## History and Name The name pyrobelonite comes from the Greek words *pyr* (πυρ) meaning "fire" and *belone* (βελόνη) meaning "needle", an allusion to its typical color and crystal habit. The mineral was first described in 1888 by L.J. Igelström and A. Sjögren based on specimens found in the Långban mine in Sweden. ## Uses Due to its rarity and small accumulations, pyrobelonite has no industrial applications. It is solely an object of interest for mineral collectors.

Properties

Mohs hardness: 3.5
Luster: Adamantine to greasy
Streak: Yellowish
Density: 5.46-5.50
Cleavage: Good on {010}
Fracture: Conchoidal to uneven
Transparency: Transparent to translucent
Crystal system: Orthorhombic

Diagnostic features

## Identification Pyrobelonite can be identified by its intense, reddish-orange color, adamantine luster, and characteristic, acicular or slender prismatic crystals, often forming radial aggregates. High density is also helpful. ## Distinguishing from Similar Minerals It can be confused with vanadinite, which crystallizes in the hexagonal system (not orthorhombic) and usually forms hexagonal, tabular or prismatic crystals. Descloizite, another lead vanadate, has a similar composition but typically forms different crystal habits and occurs in different associations. ## Crystal Habits It forms elongated, prismatic crystals with a nearly square cross-section, as well as thin, acicular crystals (acicular habit). These crystals often occur as fan-shaped or radial aggregates.

Geological environment

## Genesis It is a secondary mineral, forming in the oxidation zones of ore deposits, especially in metamorphosed iron and manganese deposits. ## Mineral Associations It most commonly co-occurs with other manganese and lead minerals, such as hausmannite, pyrochroite, manganite, barite, rhodonite, and other rare minerals from the Långban deposit, such as manganberzeliite. ## Localities The most important and classic locality is Långban in Värmland, Sweden (type locality). Significant specimens also come from the Franklin and Sterling Hill deposits in New Jersey, USA, as well as from the Kombat mine in Namibia.

Rarity

Rare

For collectors

## Quality Criteria Specimens with sharp, well-terminated crystals of intense, "fiery" color and strong luster are most highly valued. Radial aggregates on a contrasting rock matrix are particularly sought after. Crystal size and lack of damage significantly increase the value of a specimen. ## Popular Localities Specimens from Långban, Sweden, and Franklin, USA, are considered classics and fetch the highest prices on the collector's market.

Care and storage

## Cleaning Specimens should be cleaned very carefully, using a soft brush and, if necessary, distilled water. Ultrasonic cleaners should be avoided, as they can damage delicate crystals. ## What to Avoid The mineral is sensitive to acids. As a lead mineral, it is toxic – avoid inhaling dust and wash hands after any contact. Protect it from impacts and scratching by harder minerals. ## Storage It is recommended to store specimens in separate, padded boxes or display cases to prevent mechanical damage. Avoid exposure to dusty or humid environments.

Sources

IMA Mineral List (CNMNC)