Lévyne-Na

Chemical formula: Na<sub>6</sub>(Si<sub>12</sub>Al<sub>6</sub>)O<sub>36</sub>·18H<sub>2</sub>O

Levyne-Na is a rare mineral from the zeolite group, forming tabular, hexagonal crystals, found in gas vesicles of basic volcanic rocks.

## Characteristics Levyne-Na is a hydrated sodium aluminosilicate, belonging to the zeolite group. It forms characteristic, thin, tabular crystals with a hexagonal outline, which often arrange into rosette-like or fan-shaped aggregates. Crystals are usually small, rarely exceeding a few millimeters in diameter. This mineral is closely related to levyne-Ca, in which calcium is dominant. ## Physical properties Levyne-Na crystals exhibit a vitreous luster. They are transparent to translucent. Hardness on the Mohs scale ranges from 4 to 4.5, and density is approximately 2.1 g/cm³, which is typical for zeolites. ## Colors and varieties Levyne-Na is most often colorless or white. No colored or commercial varieties are distinguished. ## History and name The mineral's name refers to its chemical composition, in which sodium (Na) is the dominant element at a specific position in the crystal structure, and to its relationship with the older, calcium analogue – levyne. Levyne was named after the French mineralogist Armand Lévy (1795-1841). Levyne-Na was formally recognized as a distinct mineral species by the International Mineralogical Association (IMA) in 1997 as part of the redefinition of the levyne group. ## Applications Levyne-Na, like other rare zeolites, has no industrial significance. However, it is a valued and sought-after mineral by collectors specializing in this group of minerals.

Properties

Mohs hardness
4-4.5
Luster
Vitreous
Streak
White
Density
2.09-2.11
Cleavage
Good on {0001}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Trigonal

Diagnostic features

## Identification Levyne-Na can be identified by its characteristic, thin, tabular crystals with a hexagonal outline, often forming rosette aggregates. Its occurrence in gas vesicles in volcanic rocks is also an important clue. Vitreous luster and low hardness aid in identification. ## Distinguishing from similar minerals Levyne-Na is visually indistinguishable from levyne-Ca. Definitive differentiation requires advanced chemical analysis (e.g., EDS). It can be confused with other tabular zeolites, such as chabazite-Na, but levyne crystals are usually much thinner and more platy. It is distinguished from quartz by its significantly lower hardness. ## Crystal forms Crystals are thin to thick, tabular, with a hexagonal outline. They often form rosette, fan-shaped, or spherulitic aggregates. Sometimes they occur as penetration twins.

Geological environment

## Genesis Levyne-Na is a low-temperature hydrothermal mineral. It forms as a product of crystallization from aqueous solutions in vesicles and fissures within basic volcanic rocks, such as basalts and phonolites. It is one of the secondary minerals that form after lava solidification. ## Mineral associations This mineral often co-occurs with other zeolites, such as analcime, natrolite, chabazite-Na, gmelinite-Na, thomsonite-Ca, as well as calcite and apophyllite. ## Localities The most important and classic localities for levyne-Na are in Australia, particularly in Tasmania (Gads Hill, Redpa) and Victoria (Phillip Island, Flinders). It is also known from several localities in the USA, including Oregon (Springfield) and Washington (quarries above the Cowlitz River). Occurrences have also been reported in Germany (Hesse) and Italy (Sicily).

Rarity

Rare

For collectors

## Quality criteria Most valued by collectors are specimens with well-formed, sharp, and clearly separated crystals forming aesthetic, rosette aggregates. Transparency and lack of damage are important. A contrasting matrix significantly enhances the specimen's attractiveness. Crystal size is also an important factor, although even millimeter-sized but perfectly formed crystals are highly prized. ## Popular localities Specimens from classic localities in Tasmania and Victoria, Australia, are considered the best and most desirable by collectors specializing in zeolites.

Care and storage

## Cleaning Specimens should be cleaned very carefully, using a soft brush to remove dust. Brief rinsing in distilled water is permissible, followed by thorough drying. Ultrasonic cleaners should be avoided, as they can damage delicate crystals. ## What to avoid Contact with acids and other chemicals should be avoided. As a hydrated mineral, levyne-Na is sensitive to high temperatures, which can cause dehydration and destruction of its structure. It should not be heated or stored in very dry conditions. ## Storage Levyne-Na specimens are best stored in closed collector's boxes or display cases, protecting them from dust, mechanical damage, and sudden temperature changes. Due to its fragility, it should be avoided placing it in direct contact with harder minerals.

External references

Sources

Read more