Junkite

Junkite is a fictional mineral frequently used in geology education to illustrate the process of mineral description and reporting. It is described as a hydrated alkali-aluminosilicate with a monoclinic crystal system. The proposed formula is NaAlSi3O8·2H2O, with a Mohs hardness of 5.5 to 6 and a specific gravity of about 3.0 g/cm3. In illustrative scenarios, junkite forms by metasomatic alteration of feldspar-bearing rocks under low-temperature conditions and is typically found in small, display-size crystals in teaching collections.

In terms of appearance, junkite is described as colorless to pale blue with a vitreous luster; crystals are prismatic with a typical length-to-width ratio of 2:1.

The mineral is named as a pedagogical placeholder; the name is not tied to a real locality. In educational contexts, junkite serves to demonstrate proper mineral naming conventions, reporting of crystallography, and the interpretation of physical properties.

See also: mineral, silicate minerals, mineral systematics.