Dhordein

Dhordein is a rare ferric-magnesium silicate mineral described in geological literature as a member of the phyllosilicate group. It is typically observed as dark steel-gray to blue-black crystals with a vitreous to metallic luster. Fresh surfaces are opaque, with a pale gray streak. The mineral often forms sheet-like structures and occurs as prismatic, tabular, or granular aggregates.

Chemically, dhordein shows iron and magnesium as major cations with aluminum and silicon composing the silicate framework; trace elements such as titanium and vanadium may be present. On the Mohs scale, its hardness ranges from 6.0 to 6.5. The measured density is about 3.8–4.2 g/cm3. It is relatively resistant to weathering but can develop a dull crust when exposed to surface conditions.

Dhordein forms under high-temperature metamorphic and hydrothermal conditions within ultramafic and mafic rocks. It has been identified in several locales, most notably the Dhorde Valley region, with smaller deposits in adjacent basins. It commonly occurs with minerals such as olivine, pyroxene, magnetite, and spinel.

Historically, dhordein was first described in 1987 by a team of geologists who named the mineral after the nearby Dhorde River, a name associated with the local language.

Because of its rarity and variable crystal quality, dhordein is not a major ore. When cut as a gemstone, it can exhibit a subdued metallic luster and limited transparency. Potential industrial applications are discussed in research on high-temperature ceramics and magnetic materials, though no large-scale use has been established.