Tomsquarryite

Chemical formula: NaMgAl<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>(OH)<sub>6</sub>·8H<sub>2</sub>O

Tomsquarryite is a rare phosphate mineral, forming tiny, colorless or white crystals with a hexagonal outline, discovered in Tom's Quarry.

## Characteristics Tomsquarryite is a hydrated sodium, magnesium, and aluminum phosphate. It occurs as very small, tabular crystals with a hexagonal outline, not exceeding 0.2 mm. These crystals form rosette-like or radial aggregates, as well as thin, brittle crusts on rock surfaces. Individual crystals are typically colorless to white and transparent. ## Physical Properties This mineral is characterized by a hardness of approximately 2 on the Mohs scale, making it very soft. It has a pearly luster on cleavage surfaces and a vitreous luster on other faces. It is a light mineral, with a density of 2.26 g/cm³. ## History and Name The mineral's name comes from its discovery locality – Tom’s Quarry in Kapunda, South Australia. It was formally described and approved by the International Mineralogical Association (IMA) in 2021. The discovery was made by Australian mineralogists. ## Applications Due to its extreme rarity and microscopic crystal sizes, tomsquarryite has no industrial applications. It is solely an object of scientific interest and a collector's item for specialized micromineral collectors.

Properties

Mohs hardness
2
Luster
Pearly
Streak
White
Density
2.26
Cleavage
Perfect on {0001}
Fracture
Uneven
Transparency
Transparent
Crystal system
Trigonal

Diagnostic features

## Identification Identifying tomsquarryite under amateur conditions is practically impossible and requires advanced analytical methods, such as Raman spectroscopy or chemical analysis (EDS). Preliminary identification under a microscope is based on observing characteristic, hexagonal, tabular crystals forming rosette-like aggregates on phosphate rocks from the type locality. ## Distinguishing from Similar Minerals It can be confused with other secondary phosphate minerals occurring in the same association, such as minyulite or wavellite. Differentiation requires specialized studies, as visually these minerals can form similar, tiny, white coatings and aggregates. ## Crystal Forms It forms thin, tabular crystals with a hexagonal outline. These crystals combine into small, radial or rosette-like aggregates, and also form thin, brittle crusts.

Geological environment

## Genesis Tomsquarryite is a secondary phosphate mineral. It forms in the weathering zone of phosphorite deposits, as a result of the interaction of hydrothermal solutions or surface waters with rocks rich in aluminum and phosphorus. In its type locality, it formed in voids within phosphate breccia. ## Mineral Associations It co-occurs with other rare phosphate minerals, such as minyulite, wavellite, crandallite, fluorapatite, and quartz. ## Localities The only confirmed occurrence of tomsquarryite in the world is its type locality – Tom’s Quarry, located near Kapunda in the Mount Lofty Ranges, South Australia.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of collector specimens depends on the abundance and aesthetics of the microscopic aggregates. Samples with clearly formed, rosette-like crystal clusters, contrasting with the color of the host rock, are most valued. The size of individual crystals, although always microscopic, is also important – the larger and better-formed they are, the more valuable the specimen. ## Popular Localities The only source of specimens is Tom’s Quarry in South Australia. Material from this locality is extremely limited and sought after by collectors specializing in rare species and microminerals.

Care and storage

## Cleaning Specimens should be cleaned only very carefully, using compressed air to remove dust. Due to extreme fragility and softness, any mechanical contact, including with brushes, should be avoided. Washing in water, especially ultrasonic cleaning, is absolutely inadvisable and can destroy the specimen. ## What to Avoid Avoid contact with water, chemicals (acids and bases), and high temperatures, which can cause dehydration and destruction of the mineral's structure. Specimens are very fragile and sensitive to shocks and changes in humidity. ## Storage It is recommended to store specimens exclusively in specialized micromount boxes, under stable room conditions, away from sources of vibration, dust, and direct sunlight.

Sources

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