Dzhalindite
Chemical formula: In<sup>3+</sup>(OH)<sub>3</sub>
A very rare indium hydroxide, most often forming microscopic aggregates or pseudomorphs of a yellowish-brown color.
Properties
- Mohs hardness
- 3.5-4.5
- Luster
- Greasy to Sub-Adamantine
- Streak
- Light yellow to yellowish brown
- Density
- 4.36-4.4
- Cleavage
- Perfect on {001}, not observed
- Fracture
- Conchoidal to uneven
- Transparency
- Translucent to Opaque
- Crystal system
- Cubic
Diagnostic features
## Identification Helpful features for identifying dzhalindite include its characteristic yellowish-brown color, greasy luster, and relatively high density. The geological context is key - its occurrence in the oxidation zones of tin deposits, in association with other indium minerals. It often occurs as pseudomorphs after indite. ## Distinguishing from similar minerals Dzhalindite can be confused with common goethite or other minerals from the limonite group, which have a similar color. However, goethite has a distinctly yellowish-brown streak and is significantly lighter. Sphalerite of a similar color is distinguished by its perfect cleavage. Certain distinction from these minerals requires advanced studies, such as X-ray microanalysis (EDS/WDS) to confirm the presence of indium. ## Crystal forms Most commonly found as massive, granular, earthy aggregates or as pseudomorphs after regular indite crystals. Very rarely forms its own microscopic crystals in the form of cubes.
Geological environment
## Genesis Dzhalindite is a secondary mineral, forming in the oxidation (weathering) zones of hydrothermal ore deposits, especially tin-bearing greisens. It forms as a result of the alteration of primary indium sulfides, such as indite (FeIn₂S₄) and roquesite (CuInS₂). ## Mineral associations It most often co-occurs with cassiterite, quartz, indite, roquesite, as well as sphalerite and chalcopyrite. ## Localities The most important occurrences of this mineral in the world are the type locality - the Dzhalinda deposit in Russia, as well as the Mount Pleasant deposit in New Brunswick, Canada. In Poland, dzhalindite has been found in tin-bearing greisens in Gierczyn, Lower Silesia (Izera Mountains), which is one of the few confirmed occurrences in Europe.
Rarity
Very rare
For collectors
## Quality criteria The collecting value of dzhalindite is primarily determined by its extreme rarity. Specimens rich in this mineral, forming macroscopically visible aggregates or distinct pseudomorphs, are most highly prized. Any, even microscopic, well-formed crystals are considered exceptional. Association with other rare minerals, such as indite or roquesite, is also of great importance. ## Popular localities Apart from material from the type locality in Russia, specimens from Mount Pleasant in Canada and from Gierczyn, Poland, are best known on the collector's market, representing a great rarity and being sought after by specialized collectors.
Care and storage
## Cleaning Dzhalindite specimens should only be cleaned mechanically, using a soft brush to remove dust. Due to its rarity and potential reactivity, contact with water and any chemical agents should be avoided. If liquid is necessary, only distilled water is permissible, and the specimen should be dried immediately. ## What to avoid The mineral is sensitive to acids, which can damage or completely dissolve it. It should be protected from mechanical damage and friction, as it is relatively soft. Cleaning in ultrasonic cleaners is not recommended. ## Storage It is recommended to store specimens in separate, closed display boxes, away from harder minerals that could scratch them. A label with the name and location is crucial for preserving its scientific and collecting value.