terrassidel

Terrassidel is a hypothetical mineral described in speculative geology to illustrate mineral formation in terrace-related environments. The name combines terrace with the common mineral suffix -del and is not recognized by major mineral databases. In educational models it serves to discuss how layered hydrothermal systems can yield distinct crystal habits.

The term terrassidel originated in a 2007 classroom model by geologist Elena Ruiz, designed to explore mineral diversity on volcanic-terrace formations along coastal regions. It has since appeared in teaching materials and fictional case studies about terrace deposits.

In the model, terrassidel is a framework silicate with a layered, sheet-like structure and monoclinic symmetry. The major cations are aluminum and calcium, with sodium and potassium as trace components; the approximate empirical composition is described as a silicon-oxygen framework with mixed cations. The mineral is portrayed as forming at relatively low temperatures in hydrothermal fluids near terrace conveyors, though no natural specimen has been confirmed.

Physical properties commonly attributed in simulations include a Mohs hardness around 5–6, a vitreous to resinous luster, and a pale green to pale blue color. It is described as translucent to near transparent with a conchoidal to uneven fracture and two-directional cleavage.

Because terrassidel is not an established mineral, it is mainly of educational and speculative interest. In real-world practice, researchers study terrace geologies through known minerals such as quartz, clays, zeolites, and calcite.

See also: terrace geology, hydrothermal minerals, silicate minerals.