Nasonite

Chemical formula: Ca₄Pb₂+₆(Si₂O₇)₃Cl₂

Nasonite is a rare lead calcium silicate, characterized by hexagonal crystals and often a white coloration.

## Characteristics Nasonite is a lead calcium silicate that typically forms hexagonal crystals with a prismatic or tabular habit. It often occurs as radial or fibrous aggregates. Typical nasonite specimens are white, although varieties with a delicate yellow or blue-green tint are rarer. ## Physical Properties The Mohs hardness of nasonite is 4. This mineral exhibits a good vitreous luster. It is transparent to translucent. The specific gravity of nasonite is 5.42 g/cm³. It has good cleavage along the basal plane {0001} and indistinct prismatic cleavage. ## Colors and Varieties The most commonly encountered nasonite is white. Rarer specimens have a delicate yellow or blue-green hue, which may be associated with the presence of trace amounts of other elements. ## History and Name Nasonite was discovered in 1899. The mineral is named after Frank L. Nason (1856-1928), an American mining engineer and geologist who first described this mineral. ## Uses Nasonite has no industrial applications. It is a mineral of interest mainly to collectors due to its rarity and the aesthetics of its crystals.

Properties

Mohs hardness: 4
Luster: Szklisty
Streak: White
Density: 5.42
Cleavage: Good on {0001} indistinct prismatic
Fracture: Nierówny
Transparency: Transparent,Translucent
Crystal system: Hexagonal

Diagnostic features

## Identification Nasonite can be identified by its hexagonal crystal habit, white color (rarely yellow or blue-green), vitreous luster, and a Mohs hardness of 4. Its high density is also characteristic. ## Distinguishing from Similar Minerals Nasonite can be confused with other white minerals of similar habit, but its high density and the presence of lead in its chemical composition are diagnostic features. Chemical analysis or X-ray diffraction can confirm the mineral's identity. ## Crystal Forms Nasonite typically forms hexagonal crystals with a prismatic or tabular habit. It often occurs as radial or fibrous aggregates, which gives it a characteristic appearance.

Geological environment

## Genesis Nasonite is a secondary mineral, forming in the oxidation zones of lead ore deposits. It occurs in lead- and silicon-rich environments, often in association with other secondary minerals. ## Mineral Associations Nasonite often co-occurs with other secondary lead minerals, such as cerussite, anglesite, as well as with quartz and calcite. ## Localities The most famous nasonite localities are in Franklin and Sterling Hill, New Jersey, USA, where it was discovered. Other occurrences include Långban in Sweden and some deposits in Germany.

Rarity

Very Rare

For collectors

## Quality Criteria The most prized nasonite specimens are those that exhibit well-formed, transparent or translucent crystals with a distinct hexagonal habit. Large, aesthetic radial aggregates are also highly sought after. Color purity and absence of mechanical damage affect the value of the specimen. ## Popular Localities Specimens from Franklin and Sterling Hill, New Jersey, USA, are particularly valued by collectors due to their historical significance and the quality of the crystals found there.

Care and storage

## Cleaning Nasonite can be cleaned gently using a soft brush and lukewarm water. For more stubborn dirt, distilled water can be used to avoid hard water deposits. ## What to Avoid Avoid using strong chemical agents that can damage the mineral's surface. Prolonged exposure to direct sunlight can potentially affect its color, so it is recommended to store it in a shaded place. Also, avoid sudden temperature changes. ## Storage Nasonite is best stored in enclosed display cases or boxes, away from dust and moisture. Due to its moderate hardness, avoid contact with harder minerals that could scratch it.

External references

https://www.mindat.org/min-2844.html