Indite
Chemical formula: Fe<sup>2+</sup>In<sup>3+</sup><sub>2</sub>S<sup>2-</sup><sub>4</sub>
Indite is a very rare iron indium sulfide, forming small, metallic grains in hydrothermal veins.
Properties
- Mohs hardness
- 5
- Luster
- Metallic
- Streak
- Black
- Density
- 4.5-4.6
- Cleavage
- Imperfect on {111}
- Fracture
- Uneven
- Transparency
- Opaque
- Crystal system
- Cubic
Diagnostic features
## Identification Identification of indite is impossible without advanced laboratory techniques. Due to its occurrence as microscopic grains embedded in other minerals (mainly cassiterite), identification relies on analysis by reflected light ore microscopy and chemical analysis (e.g., using an electron microprobe) to confirm the presence of iron and indium. ## Distinguishing from Similar Minerals It can be confused with other fine, metallic sulfides, such as sphalerite, chalcopyrite, or stannite, with which it often co-occurs. Visual differentiation is impossible; it requires specialized chemical and crystallographic analysis. ## Crystal Forms Indite crystallizes in the isometric system, forming spinel-habit crystals. However, in nature, it is observed almost exclusively in the form of irregular, rounded grains and anhedral aggregates (lacking developed faces).
Geological environment
## Genesis Indite is a mineral of hydrothermal origin. It forms in quartz-sulfide veins associated with greisens and tin deposits. It forms under high-temperature conditions, crystallizing from solutions rich in sulfur, iron, indium, and other metals. ## Mineral Associations It most commonly co-occurs with cassiterite, in which it forms small inclusions. It is also accompanied by other sulfide minerals, such as chalcopyrite, sphalerite, stannite, dzhalindite (another indium sulfide), and arsenopyrite. ## Localities This is an extremely rare mineral. Besides the type locality in Kazakhstan, its presence has been reported in several other locations worldwide, including the Mount Pleasant tin-tungsten deposit in New Brunswick (Canada) and in Japan.
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of an indite specimen is not assessed based on visual criteria, such as color or form, because this mineral occurs in microscopic form. The scientific and collector's value of a specimen lies solely in the confirmed presence of indite, documented by analysis. The most valuable samples are those from the type locality or those that contain relatively "large" (on a microscopic scale) or numerous indite grains, clearly visible in analytical studies.
Care and storage
## Cleaning Due to its extreme rarity and microscopic nature, indite specimens (typically in the form of polished sections for microscopic examination) should not be cleaned by collectors. Any conservation treatments should be left to specialized laboratories. ## What to Avoid Avoid contact with chemicals, especially acids, which can react with sulfides. Also avoid ultrasonics and any form of mechanical cleaning that could damage the delicate grains and the surrounding rock. ## Storage Specimens containing indite should be stored under stable conditions, in a dry environment, away from contaminants and direct sunlight. The safest storage method is a specialized collector's box or display case that protects against dust and mechanical damage.