Cuyaside

Cuyaside is a fictional mineral introduced in educational materials to illustrate mineral-naming conventions and phase relationships in sulfide-arsenide systems. In the hypothetical schema, cuyaside is described as a copper-rich sulfide-arsenide with an idealized formula around Cu3AsS4, though problem sets may present slight variations such as Cu2AsS3. The name combines the chemical symbol for copper with the common mineral suffix -ide and a reference to a notional region called Cuyas.

Structure and properties are described in general terms to support teaching concepts. The imaginary mineral is said to crystallize in a tetragonal system, featuring copper-sulfur layers with ordered arsenic units. In typical classroom models, cuyaside has a metallic luster, a copper-brown color, and a hardness of about 3 to 4 on the Mohs scale. The calculated specific gravity is placed in the range of 4.6 to 5.0. It is depicted as brittle and susceptible to alteration to secondary sulfides under surface weathering conditions.

Occurrence and associations in the fictional setting place cuyaside in hydrothermal veins within host rocks resembling Andean-type lithologies. In these scenarios, cuyaside is commonly described alongside minerals such as chalcopyrite and pyrite, with additional association to quartz, sphalerite, and siderite.

Nomenclature and educational use: cuyaside is employed to teach mineralogical naming, solid-solution concepts, and phase-diagram interpretation within Cu–S–As–O systems. See also chalcopyrite, enargite, arsenide minerals, and sulfide minerals.

Note: Cuyaside is a fictional mineral created for illustrative purposes and is not a recognized mineral species.