Sassite
Chemical formula: Ti<sup>3+</sup><sub>2</sub>Ti<sup>4+</sup>O<sub>5</sub>
Sassait is an extremely rare titanium oxide, forming microscopic, black crystals with a metallic luster, found so far in only one location worldwide.
Properties
- Mohs hardness
- 6-7
- Luster
- Metallic
- Streak
- Black
- Density
- 4.23
- Cleavage
- Perfect on {100}
- Fracture
- Brittle
- Transparency
- Opaque
- Crystal system
- Monoclinic
Diagnostic features
## Identification Identification of sassait is impossible without advanced laboratory equipment. It requires the use of a scanning electron microscope (SEM) with chemical composition analysis (EDS) and X-ray diffraction (XRD) to confirm the crystal structure. Visually, under high magnification, they appear as tiny, black, metallic-lustered laths or tabular crystals. ## Distinguishing from similar minerals Sassait co-occurs with other black, metallic titanium minerals such as tistarite and grossmanite. Distinguishing it from them is only possible based on precise chemical and structural analysis. It differs from them in stoichiometry (the ratio of trivalent to tetravalent titanium) and crystallographic system. ## Crystal forms Sassait forms very small, elongated, lath-like or thin-tabular crystals. They usually occur as single, isolated crystals embedded in corundum xenoliths.
Geological environment
## Genesis Sassait forms under unique geological conditions, associated with high-temperature and low-pressure volcanism. It was found in xenoliths (fragments of foreign rock) rich in corundum, which were trapped and transported to the surface by basanite lava. It forms in an extremely reducing environment, which allows for the stabilization of trivalent titanium (Ti³⁺). ## Mineral associations This mineral co-occurs with other rare titanium and rare earth element minerals, such as tistarite, grossmanite, carmeltazite, corundum, anorthite, hibonite, and osbornite. ## Localities The only confirmed locality of sassait in the world (type locality) is the volcanic formation of Mount Carmel in northern Israel. This mineral is found within corundum xenoliths mined by the Shefa Yamim company.
Rarity
Extremely rare
For collectors
## Quality criteria In the case of such a rare micromineral as sassait, the main criterion for value is the mere confirmation of its presence on a sample. The most highly prized specimens are those where the crystals, despite their microscopic size, are well-formed, undamaged, and as large as possible (though still under 1 mm). The aesthetics of the host rock and the richness of associated minerals are also important. ## Popular localities The only source of sassait specimens is Mount Carmel in Israel. The material comes from the mining activities of Shefa Yamim, which searches for sapphires and other gemstones there. Specimens reach the collector's market in very limited quantities.
Care and storage
## Cleaning Specimens containing sassait, due to their microscopic size and embedding in the host rock, generally do not require and should not be cleaned. Any attempt at mechanical cleaning (e.g., with a brush) risks irreversible damage or loss of the crystals. ## What to avoid Avoid contact with any chemicals, acids, and ultrasonic cleaners. Specimens should be protected from dust, vibrations, and sudden temperature changes. ## Storage Sassait samples must be stored in specialized micromount boxes, which protect them from mechanical damage and contamination. Direct exposure to sunlight should be avoided, although there is no evidence of its negative impact.