Amoraite

Chemical formula: Ca<sub>12</sub>Al<sub>6</sub>(OH)<sub>36</sub>(CO<sub>3</sub>)<sub>2</sub>(S<sup>4+</sup>O<sub>3</sub>)·15H<sub>2</sub>O

Amorite is a newly discovered, extremely rare mineral from the ettringite group, found in a single locality in Jordan.

## Characteristics Amorite is an extremely rare mineral, approved by the International Mineralogical Association (IMA) in 2023. It occurs in the form of very small, hexagonal, tabular crystals that form rosette-like aggregates. Individual crystals reach a size of up to 20 micrometers. Due to the microscopic size of the crystals, visual features visible to the naked eye are limited to the appearance of entire aggregates, which form white, chalky coatings on the host rock. ## Physical Properties The crystals are too small to determine their hardness, density, or other physical properties in a standard way. The luster has been described as vitreous. The mineral is non-fluorescent under ultraviolet light. ## Colors and Varieties Amorite is colorless in the form of individual crystals, and its aggregates are white. No varieties have been distinguished. ## History and Name The mineral's name comes from the Amorites, an ancient Semitic people who inhabited the territory of modern-day Jordan, where the mineral was discovered. It was found in the Hatrurim Formation at the Daba-Siwaqa type locality in Jordan. Its discovery and characterization were published in 2024 by a team of mineralogists, including Evgeny V. Galuskin. ## Applications Amorite has no industrial applications. Its significance is purely scientific and collectible, as a unique and newly described mineral species.

Properties

Luster
Vitreous
Streak
White
Cleavage
Perfect on {0001}
Fracture
Uneven
Transparency
Transparent
Crystal system
Hexagonal

Diagnostic features

## Identification Identification of amorite is impossible without advanced laboratory techniques. It requires chemical analysis (EDS) and X-ray diffraction (XRD) methods to confirm its unique crystal structure and chemical composition. Visually, in the form of white, rosette-like aggregates, it is indistinguishable from many other secondary minerals. ## Distinguishing from Similar Minerals Amorite is very similar to other minerals from the ettringite group, such as ettringite, thaumasite, and sturmanite. Differentiation requires specialized analysis to identify the presence of the sulfite ion (SO₃)²⁻, which is characteristic of amorite. ## Crystal Forms The mineral forms hexagonal, tabular crystals with a hexagonal outline. These crystals combine to form characteristic, rosette-like aggregates.

Geological environment

## Genesis Amorite forms as a result of low-temperature hydrothermal processes occurring in metamorphic rocks of the Hatrurim Formation (the so-called "mottled marble"). It forms in veins cutting pyroxene-garnet rocks, which are products of combustion and pyrometamorphism of marls and limestones. ## Mineral Associations This mineral co-occurs with other rare minerals from the ettringite group, such as bentorite, as well as with calcite, afwillite, and other contact metamorphic minerals. ## Localities The only confirmed occurrence of amorite in the world is its type locality: the Daba-Siwaqa area within the Hatrurim Formation in Jordan.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of amorite specimens is assessed primarily based on the richness and development of microscopic aggregates on the host rock. The most valuable samples are those where the rosette-like clusters are numerous, well-formed, and clearly visible under a microscope. Association with other rare minerals from this locality is also important. ## Popular Localities The only source of specimens is the type locality in Jordan. Material from this location is extremely difficult to obtain and appears on the collector's market very sporadically, mainly in specialized circles.

Care and storage

## Cleaning Due to its extreme rarity, microscopic size, and delicacy, amorite specimens should not be cleaned mechanically or chemically. Any attempts at cleaning may irreversibly destroy the mineral. ## What to Avoid Avoid contact with water, acids, chemical agents, and ultrasound. Specimens should be protected from vibrations, shocks, and abrasion. They should not be exposed to high temperatures or direct sunlight. ## Storage Amorite specimens should be stored exclusively in specialized, padded "micromount" boxes, protecting them from dust, moisture, and mechanical damage. It is best to store them under stable room conditions.

Sources

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