Trhlin

Trhlin is a hypothetical mineral described in speculative mineralogy and used in various science-fiction and theoretical discussions. It is classified as a silicate mineral with a layered crystal structure that allows for stacking of tetrahedral units and interlayer cations. The exact chemical composition is reported with some variability in sources.

Commonly reported properties place trhlin at Mohs hardness around 6 to 7, with a vitreous to pearly luster. Colors range from pale blue to deep gray, often depending on trace elements. Crystals are typically prismatic, with good cleavage along one plane.

Trhlin is said to form in high-temperature metamorphic environments and in hydrothermal systems associated with ultramafic rocks. It is reported to occur together with minerals such as quartz, spinel, and olivine. Its stability is thought to be influenced by pressure and fluid composition.

Origin of the name is fictional; "trhlin" is derived from a convention used in speculative texts. The mineral has appeared in catalogs of fantasy geology and in discussions within theoretical mineralogical frameworks, where it serves as a model for layered silicates.

Use and significance: Because trhlin is not a confirmed mineral, practical applications are not established. It is commonly used as a pedagogical example in crystallography and mineral physics to illustrate layered silicate structures and the effects of interlayer cations on properties.