Hematophanite
Chemical formula: Pb²⁺₄Fe³⁺₃O₈(Cl,OH)
Hematophanite is a very rare lead iron oxyhalide, forming thin, tabular crystals with an intense, reddish-brown color and metallic luster.
Properties
- Mohs hardness
- 2-3
- Color
- Deep red-brown
- Luster
- Submetallic to resinous
- Streak
- Yellow-red, orange
- Density
- 7.70
- Cleavage
- On {001}, micaceous.
- Fracture
- Uneven
- Transparency
- Transparent,Opaque
- Crystal system
- Tetragonal
Diagnostic features
## Identification Hematophanite can be identified by its characteristic thin-tabular form, hexagonal crystal outline, and intense reddish-brown color. Key features also include very high density, strong, almost metallic luster, and very low hardness. In transmitted light, on thin edges, it exhibits a diagnostic, blood-red color. ## Distinguishing from Similar Minerals It can be confused with hematite, which, however, is much harder (5.5-6.5) and has a reddish-brown streak. Other similar lead minerals, like wulfenite, typically have different colors (yellow, orange) and lower density. Thin mica flakes (e.g., biotite) are much lighter and more flexible. ## Crystal Forms Hematophanite crystals are thin, tabular, with a hexagonal or pseudohexagonal outline. They often form fan-shaped, rosette-like, or radial aggregates, as well as irregular clusters of flakes.
Geological environment
## Genesis Hematophanite is a secondary mineral, forming in the oxidation zones of ore deposits where lead and iron minerals are present. It forms as a result of the alteration of other minerals in a chlorine-rich environment. Its formation is associated with low-temperature hydrothermal processes or weathering. ## Mineral Associations It co-occurs with other rare secondary minerals, such as nadorite, mendozite, as well as more common minerals like galena, sphalerite, hematite, magnetite, calcite, and quartz. ## Localities The most important and classic locality (type locality) is Långban and nearby Jakobsberg in the Värmland region of Sweden. These are the only confirmed and well-documented occurrences of this mineral worldwide.
Rarity
Very rare
For collectors
## Quality Criteria The most highly valued hematophanite specimens are those with well-formed, sharply terminated crystals of intense reddish-brown color and strong luster. Rich clusters of crystals forming aesthetic, rosette-like or fan-shaped aggregates on a contrasting matrix (e.g., on calcite) are particularly sought after. Due to the mineral's rarity, any well-defined microcrystal is valuable for collectors specializing in systematics or minerals from Långban. ## Popular Localities The only source of collector specimens are the historic mines in Långban and Jakobsberg in Sweden. Specimens from these localities are classics and set the standard against which all others are judged.
Care and storage
## Cleaning Hematophanite specimens should only be cleaned mechanically, using a soft brush to remove dust. Due to its softness, hard tools should be avoided. The use of water is not recommended, and if necessary, it should be distilled water, used minimally and immediately dried. ## What to Avoid Contact with acids and other chemicals, which can damage it, must be strictly avoided. The mineral is very soft and susceptible to scratches. It should be protected from impacts and drops. It should not be heated or subjected to ultrasound. ## Storage Store in a separate, padded box to avoid contact with harder minerals. It is best displayed in a closed cabinet, protected from dust and mechanical damage.