Zoisite-(Pb)
Chemical formula: CaPb²⁺Al₃[Si₂O₇][SiO₄]O(OH)
Zoisite-(Pb) is the lead analog of zoisite, a rare, pale pink mineral from the epidote group, discovered in the Jakobsberg mine in Sweden.
Properties
- Mohs hardness
- 6-7
- Luster
- Vitreous
- Streak
- White
- Density
- 4.13
- Cleavage
- {010}
- Transparency
- Transparent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification Key features include its pale pink color, tabular crystal habit, and occurrence in a specific geological environment. High density (4.13 g/cm³) can be helpful in distinguishing it from lighter minerals. However, definitive identification requires advanced analytical methods, such as chemical composition analysis, due to its similarity to other minerals in the epidote group. ## Distinguishing from Similar Minerals It can be confused with other pink minerals from the epidote group, such as manganiferous zoisite (thulite) or piemontite. Thulite typically has a more intense, pink to red color. Piemontite can also be pink but differs in chemical composition. Certain differentiation is mainly possible based on chemical analysis. ## Crystal Forms It forms small, tabular crystals, often aggregated into small clusters.
Geological environment
## Genesis Zoisite-(Pb) forms in metamorphic rocks that have been enriched in lead. Its genesis at the type locality (Jakobsberg) is associated with the metamorphism of iron and manganese ore deposits in a carbonate-rich environment. ## Mineral Associations At the discovery site (Jakobsberg mine), it co-occurs with minerals such as tephroite, magnetite, hematite, lead mica (hendricksite), celsian, barite, hausmannite, and calcite. ## Localities The only confirmed and detailed described occurrence of zoisite-(Pb) in the world is its type locality – the Jakobsberg mine in the Nordmark district, Värmland region, Sweden.
Rarity
Extremely rare
For collectors
## Quality Criteria As an extremely rare mineral, any well-formed crystal with a visible pink color, embedded in a rock matrix, is considered a specimen of high collector's value. The most desirable specimens are those with well-preserved, sharp crystal edges, originating from the type locality. ## Popular Localities The only source of specimens is the Jakobsberg mine in Sweden. This mineral is not commercially mined, and specimens available on the market come from historical or very limited finds.
Care and storage
## Cleaning It is recommended to clean specimens only with a soft brush to remove dust. The use of water, especially with detergents, is not advisable due to the rarity and potential reactivity of the mineral. ## What to Avoid Avoid contact with acids and other chemicals that may damage the mineral's surface. Due to the presence of lead, caution should be exercised, and inhalation of dust should be avoided. ## Storage Zoisite-(Pb) specimens should be stored under stable conditions, in a dry place, away from direct sunlight. It is best to keep them in closed collector's boxes to limit dust accumulation and protect them from mechanical damage.