Glecklerite

Chemical formula: Na(C<sub>2</sub>H<sub>3</sub>O<sub>3</sub>)<sup>1-</sup>

Glecklerite is an organic mineral – sodium acetate – forming tiny, colorless crystals, discovered at the site of a burning mine dump.

## Characteristics Glecklerite is a naturally occurring sodium acetate. It forms very small, tabular or lath-like crystals, usually not exceeding 0.2 mm in length. It occurs as single, scattered crystals or small aggregates. It is colorless and transparent, which, combined with the small size of the crystals, makes it difficult to observe with the naked eye. ## Physical Properties This mineral is characterized by low hardness, estimated at about 1 on the Mohs scale, which means it is very soft. It has a vitreous to pearly luster on cleavage surfaces. It is light, with a density close to 1.51 g/cm³. Due to its chemical nature, it is soluble in water. ## History and Name The name glecklerite honors Robert D. Gleckler, an American mineral collector from Dauphin County, Pennsylvania (USA), who first found this mineral. It was described and approved as a new mineral species by the International Mineralogical Association (IMA) in 2023. The discovery was made at the site of a burning anthracite coal dump near Williamstown, Pennsylvania.

Properties

Mohs hardness
1
Luster
Vitreous to pearly
Streak
White
Density
1.51
Cleavage
Perfect on {010}
Fracture
Uneven
Transparency
Transparent
Crystal system
Triclinic

Diagnostic features

## Identification Amateur identification of glecklerite is practically impossible due to its microscopic size and occurrence. Identification requires advanced analytical methods, such as X-ray diffraction (XRD) and chemical analysis. A key feature is its genesis associated with burning mine dumps. ## Distinguishing from Similar Minerals It can be confused with other secondary, water-soluble minerals formed in similar environments, such as other acetates (e.g., hoganite, paceite) or sulfates. Differentiation without specialized equipment is not possible. A clue is its co-occurrence with salammoniac and other fumarolic minerals. ## Crystal Forms Glecklerite crystals are very small, usually tabular or lath-like, elongated along one axis. They occur as single, isolated crystals on a substrate or in small, loose aggregates.

Geological environment

## Genesis Glecklerite is a mineral of anthropogenic origin. It forms as a result of volcanic gases (fumaroles) generated by underground fires in anthracite coal dumps. It forms as a sublimation product at temperatures below 100°C, crystallizing directly from the gas phase on rock surfaces. ## Mineral Associations This mineral occurs in association with other fumarolic minerals formed under similar conditions. It most commonly co-occurs with salammoniac (ammonium chloride) and native sulfur. ## Localities The only confirmed locality for glecklerite in the world is its type locality – the site of a burning anthracite coal dump near Williamstown, Dauphin County, Pennsylvania, USA.

Rarity

Extremely rare

For collectors

## Quality Criteria As a microscopic mineral, glecklerite is valued primarily for its mere presence in a collection, rather than for aesthetic qualities. Specimens where crystals, despite their small size, are well-formed and visible under a microscope are most highly rated. Rich co-occurrence with other minerals from this locality, especially salammoniac, is also important.

Care and storage

## Cleaning Due to its extreme delicacy and water solubility, glecklerite should not be cleaned wet. Specimens must be protected from contact with any liquid. The safest method for dust removal is to use a soft brush or a very gentle stream of compressed air from a distance. ## What to Avoid Contact with water, cleaning solutions, acids, and other chemicals must be strictly avoided. The mineral is hygroscopic and can be damaged or completely dissolved by ambient moisture. It should be protected from high humidity and sudden temperature changes. ## Storage Glecklerite specimens must be stored in dry conditions, preferably in tightly sealed containers (such as "perky boxes") with a desiccant (e.g., silica gel). They should be displayed away from direct sunlight and heat sources.

Sources

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