Moabite
Chemical formula: Ni²⁺Fe³⁺(PO₄)O
Moabite is a rare nickel and iron phosphate mineral, forming small, black, tabular crystals with a metallic luster.
Properties
- Mohs hardness
- 4-0
- Color
- very dark-brown, almost-black
- Luster
- Metallic
- Streak
- Brown
- Density
- 4.324
- Cleavage
- Perfect on {010}
- Fracture
- Uneven
- Transparency
- Translucent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification Identifying moabite requires specialized equipment, typically a stereomicroscope. Its characteristic features enable identification: black color, strong metallic luster, tabular crystal habit, and specific occurrence environment. Final confirmation of identity requires advanced analytical methods, such as X-ray diffraction (XRD) or Raman spectroscopy. ## Distinguishing from similar minerals Moabite can be confused with other black, metallic-lustered secondary minerals found in the oxidation zones of deposits, such as some manganese oxides (e.g., pyrolusite, hollandite) or other rare phosphates. Distinguishing it with the naked eye is practically impossible. Key to identification is its co-occurrence with other rare phosphate and sulfate minerals from the same locality. ## Crystal forms Moabite crystallizes in the monoclinic system. It forms very small, thin, tabular crystals, often with outlines resembling rectangles or hexagons. Crystals occur as single, scattered individuals on the surface of the host rock.
Geological environment
## Genesis Moabite is a secondary mineral that forms in the oxidation zone of polymetallic deposits, in this case, a uranium-vanadium deposit. Its crystallization occurs in vugs and fractures in sandstone, as a result of low-temperature hydrothermal processes. It forms from solutions rich in phosphorus, nickel, and iron, which originate from the weathering of primary ore minerals. ## Mineral associations This mineral occurs in association with other rare secondary minerals. At the type locality (Giveaway-Simplot mine), its co-occurrence with gypsum, quartz, barite, anatase, as well as other rare phosphates and sulfates such as hechtsbergite, gartrellite, juanitaite, nickelalumite, and stanfieldite has been observed. ## Localities The only confirmed locality of moabite in the world is its type locality: the Giveaway-Simplot mine, located in the White Canyon district, San Juan County, Utah, USA.
Rarity
Extremely rare
For collectors
## Quality criteria The quality of a moabite specimen is primarily assessed based on the sharpness and size of the crystals, although even the largest ones are microscopic. The most desirable specimens are those with well-formed, undamaged crystals exhibiting a strong luster, set on a contrasting substrate (matrix). The presence of other rare associated minerals on the same specimen also enhances its appeal. ## Popular localities The only source of moabite specimens is its type locality at the Giveaway-Simplot mine in Utah, USA. All specimens available on the collector's market originate from this single location.
Care and storage
## Cleaning Specimens containing moabite, typically microminerals on a rock matrix, should be cleaned with utmost care. It is recommended to use compressed air (from a safe distance) to remove dust. Avoid contact with water and any chemical agents that could damage both the mineral itself and its associated minerals. ## What to avoid Avoid ultrasonic cleaners, which can destroy or detach small crystals from the substrate. Protect from acids and other aggressive chemicals. Due to its brittleness, avoid any impacts and vibrations. ## Storage Micromounted specimens should be stored in specialized boxes (e.g., "micromount boxes") that protect them from dust, moisture, and mechanical damage. Store in stable temperature conditions, away from direct sunlight.